1. A non-transitory computer-readable storage device comprising computer-executable instructions being configured to process signals from a performance-input hardware device and comprising a laboratory module that, when executed by a computer processor, causes the computer processor to perform lab operations comprising:
presenting, via a graphical-user-interface (GUI) display, first visual information including a virtual performance-input component comprising a plurality of virtual selectors and a virtual expression part with positioning within the virtual performance-input component corresponding respectively to positioning of selector hardware components and an expression hardware component within the performance-input hardware device;
receiving a first user input for associating a particular one of the virtual selectors to a pre-established audio package;
receiving a second user input for associating the virtual expression part to an expressible tone feature of the pre-established audio package;
associating the pre-established audio package to the particular virtual selector in response to the first user input; and
associating the expressible tone feature to the virtual expression part in response to the second user input.
2. The non-transitory computer-readable storage device of claim 1, wherein the expressible tone feature is configured to affect expression of a particular tone-manipulation component selected from a group consisting of:
an effect type;
a pre-amplifier type; and
a cabinet tone type.
3. The non-transitory computer-readable storage device of claim 1 wherein:
the computer-executable instructions comprise a GUI module that, when executed by the computer processor, causes the computer processor to perform user-interface operations comprising:
presenting, via the GUI display, second visual information indicating a laboratory link corresponding to the laboratory module and a live-performance link corresponding to a stage module; and
receiving third user input indicating selection of the laboratory link; and
the laboratory operation of presenting the first visual information including the virtual performance-input component is performed in response to the third user input.
4. The non-transitory computer-readable storage device of claim 1 wherein the computer-executable instructions comprise a stage module that, when executed by the computer processor, causes the computer processor to perform live-performance operations comprising:
receiving, from the performance-input hardware device, third user input indicating the pre-established audio package, wherein the third user input is initiated at the performance-input hardware device in response to user actuation of a particular one of the selector hardware components corresponding to the particular virtual selector;
receiving a live audio signal; and
manipulating, in response to the third user input from the performance-input hardware device, the live audio signal using the pre-established audio package, yielding manipulated live audio signal.
5. The non-transitory computer-readable storage device of claim 4 wherein:
the live-performance operations further comprise presenting, via the GUI display, second visual information indicating a link to the pre-established audio package; and
the live-performance operation of receiving the third user input is performed following presentation of the second visual information and the third user input selects the link to the pre-established audio package.
6. The non-transitory computer-readable storage device of claim 5 wherein:
the computer-executable instructions comprise a GUI module that, when executed by the computer processor, causes the computer processor to perform user-interface operations comprising:
presenting, via the GUI display, third visual information indicating a laboratory link, corresponding to the laboratory module, and a live-performance link corresponding to a stage module; and
receiving fourth user input indicating the live-performance link; and
the live-performance operation of presenting the second visual information is performed in response to the fourth user input.
7. The non-transitory computer-readable storage device of claim 4 wherein:
the live-performance operations further comprise receiving, from the performance-input hardware device fourth user input indicating the expressible tone feature, wherein the fourth user input is initiated at the performance-input hardware device in response to user actuation of the expression hardware component; and
the live-performance operation of manipulating the live audio signal is performed using, in response to the fourth user input from the performance-input hardware device, the expressible tone feature, yielding the manipulated live audio signal.
8. The non-transitory computer-readable storage device of claim 7 wherein:
the live-performance operations further comprise presenting, via the GUI display, second visual information indicating a link to the expressible tone feature of the pre-established audio package; and
the live-performance operation of receiving the fourth user input is performed following presentation of the second visual information and the fourth user input selects the link to the expressible tone feature.
9. The non-transitory computer-readable storage device of claim 7 wherein:
the expressible tone feature is a first expressible tone feature;
the lab operations further comprise:
receiving fifth user input associating the virtual expression part to a second expressible tone feature of the pre-established audio package; and
associating, in response to the fifth user input, the second expressible tone feature to the virtual expression part; and
the live-performance operation of manipulating the live audio signal is performed using, in response to the fourth user input, the first expressible tone feature and the second expressible tone feature.
10. The non-transitory computer-readable storage device of claim 1 wherein:
the virtual expression part and the expression hardware component are a first virtual expression part and a first expression hardware component, respectively; and
the lab operation of presenting the first visual information comprises presenting the virtual performance-input component comprising the first virtual expression part and a second virtual expression part positioned within the virtual performance-input component corresponding respectively to positioning of the first expression hardware component and a second expression hardware component within the performance-input hardware device.
11. A non-transitory computer-readable storage device comprising computer-executable instructions being configured to process signals from a performance-input hardware device and comprising a stage module that, when executed by a computer processor, causes the computer processor to perform live-performance operations comprising:
maintaining a first association, between a particular virtual selector, of a plurality of virtual selectors, of a virtual performance-input component and a pre-established audio package stored at the computer-readable storage device;
maintaining a second association, between a virtual expression part of the virtual performance-input component and an expressible tone feature of the pre-established audio package;
receiving, from the performance-input hardware device, first user input indicating the pre-established audio package, wherein the first user input is initiated at the performance-input hardware device in response to user actuation of a particular one of a plurality of selector hardware components corresponding to the particular virtual selector which is in turn associated with the pre-established audio package;
receiving a live audio signal; and
manipulating, in response to the first user input from the performance-input hardware device, the live audio signal using the pre-established audio package, yielding manipulated live audio signal.
12. The non-transitory computer-readable storage device of claim 11 wherein:
the live-performance operations further comprise presenting, via a graphical-user-interface (GUI) display, first visual information indicating a link to the pre-established audio package; and
the live-performance operation of receiving the first user input is performed following presentation of the first visual information and the first user input selects the link to the pre-established audio package.
13. The non-transitory computer-readable storage device of claim 12 wherein:
the computer-executable instructions comprise a GUI module that, when executed by the computer processor, causes the computer processor to perform user-interface operations comprising:
presenting, via the GUI display, second visual information indicating a laboratory link, corresponding to the laboratory module, and a live-performance link corresponding to a stage module; and
receiving second user input indicating the live-performance link; and
the live-performance operation of presenting the first visual information is performed in response to the second user input.
14. The non-transitory computer-readable storage device of claim 11 wherein:
the live-performance operations further comprise receiving, from the performance-input hardware device, second user input indicating the expressible tone feature, wherein the second user input is initiated at the performance-input hardware device in response to user actuation of an expression hardware component of the performance-input hardware device; and
the live-performance operation of manipulating the live audio signal is performed using, in response to the second user input from the performance-input hardware device, the expressible tone feature, yielding the manipulated live audio signal.
15. The non-transitory computer-readable storage device of claim 14 wherein:
the live-performance operations further comprise presenting, via the GUI display, first visual information indicating a link to the expressible tone feature of the pre-established audio package; and
the live-performance operation of receiving the third user input is performed following presentation of the first visual information and the third user input selects the link to the expressible tone feature.
16. The non-transitory computer-readable storage device of claim 14 wherein:
the expressible tone feature is a first expressible tone feature;
the first expressible tone feature and a second expressible tone feature are associated in the computer-readable storage device with the virtual expression part; and
the live-performance operation of manipulating the live audio signal is performed using, in response to the second input, the first expressible tone feature and the second expressible tone feature.
17. A non-transitory computer-readable storage device comprising computer-executable instructions being configured to process signals from a performance-input hardware device and comprising a market module that, when executed by a computer processor, causes the computer processor to perform market operations comprising:
receiving, from a remote source by way of an Internet, a file including a virtual performance-input component comprising a plurality of virtual selectors and a virtual expression part, wherein:
the plurality of virtual selectors and the virtual expression part are positioned within the virtual performance-input component in a manner corresponding respectively to positioning of selector hardware components and an expression hardware component within the performance-input hardware device;
a particular one of the virtual selectors is associated with a pre-established audio package; and
the virtual expression part is associated with an expressible tone feature of the pre-established audio package.
18. The non-transitory computer-readable storage device of claim 17 further comprising a stage module that, when executed by a computer processor, causes the computer processor to perform live-performance operations comprising:
receiving, from the performance-input hardware device, first user input indicating the pre-established audio package, wherein the first user input is initiated at the performance-input hardware device in response to user actuation of a particular one of the plurality of selector hardware components corresponding to the particular virtual selector.
19. The non-transitory computer-readable storage device of claim 18, wherein the live-performance operations further comprise:
receiving a live audio signal; and
manipulating, in response to the first user input from the performance-input hardware device, the live audio signal using the pre-established audio package, yielding manipulated live audio signal.
20. The non-transitory computer-readable storage device of claim 18 wherein:
the live-performance operations further comprise presenting, via a graphical-user-interface (GUI) display, first visual information indicating a link to the pre-established audio package; and
the live-performance operation of receiving the first user input is performed following presentation of the first visual information and the first user input selects the link to the pre-established audio package.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An optical fiber communication system, comprising:
a first optical fiber having a first end and a second end which correspond to an input end and an output end for a signal beam, respectively;
a first phase conjugator operatively connected to said second end for converting the signal beam into a first phase conjugate beam and outputting the first phase conjugate beam;
a second optical fiber having a third end and a fourth end which correspond to an input end and an output end for the first phase conjugate beam, respectively;
a second phase conjugator operatively connected to said fourth end for converting the first phase conjugate beam into a second phase conjugate beam and outputting the second phase conjugate beam; and
a third optical fiber having a fifth end and a sixth end which correspond to an input end and an output end for the second phase conjugate beam;
said second optical fiber comprising a first portion located between said third end and a system midpoint and a second portion located between said system midpoint and said fourth end;
the product of the average value of the chromatic dispersion and the length of said first optical fiber being substantially coincident with the product of the average value of the chromatic dispersion and the length of said first portion;
the product of the average value of the chromatic dispersion and the length of said second portion being substantially coincident with the product of the average value of the chromatic dispersion and the length of said third optical fiber.
2. An optical fiber communication system according to claim 1, wherein
the product of the average value of the optical power and the average value of the nonlinear coefficient in said first optical fiber and the length of said first optical fiber substantially coincides with the product of the average value of the optical power and the average value of the nonlinear coefficient in said first portion and the length of said first portion, and
the product of the average value of the optical power and the average value of the nonlinear coefficient in said second portion and the length of said second portion substantially coincides with the product of the average value of the optical power and the average value of the nonlinear coefficient in said third optical fiber and the length of said third optical fiber.
3. An optical fiber communication system according to claim 1, further comprising
a plurality of optical amplifiers provided on an optical path which includes said first optical fiber, said second optical fiber and said third optical fiber.
4. An optical fiber communication system according to claim 3, wherein
the distance between each two adjacent ones of said plurality of optical amplifiers is shorter than the nonlinear length of said optical path.
5. An optical fiber communication system according to claim 1, wherein
said system midpoint is defined as a position at which the waveform distortion of the first phase conjugate beam is minimized.
6. An optical fiber communication system according to claim 1, wherein,
when said first optical fiber and said first portion are imaginarily divided into an equal number of intervals, the products of the average values of the chromatic dispersions and the interval lengths of each two corresponding intervals as counted from said first phase conjugator substantially coincide with each other and the products of the average values of the optical powers, the average values of the nonlinear coefficients and the interval lengths of the two intervals substantially coincide with each other, and,
when said second portion and said third optical fiber are imaginarily divided into an equal number of intervals, the products of the average values of the chromatic dispersions and the interval lengths of each two corresponding intervals as counted from said second phase conjugator substantially coincide with each other and the products of the average values of the optical powers, the average values of the nonlinear coefficients and the interval lengths of the two intervals substantially coincide with each other.
7. An optical fiber communication system according to claim 1, wherein
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first optical fiber and said first portion at which the accumulated values of the chromatic dispersions from said first phase conjugator are equal to each other substantially coincide with each other, and
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said second portion and said third optical fiber at which the accumulated values of the chromatic dispersions from said second phase conjugator are equal to each other substantially coincide with each other.
8. An optical fiber communication system according to claim 1, wherein
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first optical fiber and said first portion at which the accumulated values of the products of the optical powers and the nonlinear coefficients from said first phase conjugator are equal to each other substantially coincide with each other, and
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said second portion and said third optical fiber at which the accumulated values of the products of the optical powers and the nonlinear coefficients from said second phase conjugator are equal to each other substantially coincide with each other.
9. An optical fiber communication system according to claim 1, wherein
each of said first and second phase conjugators comprises
a second-order or third-order nonlinear optical medium operatively connected to said second optical fiber, and
means for pumping said nonlinear optical medium.
10. An optical fiber communication system according to claim 9, wherein
said means for pumping includes means for supplying pump light to said nonlinear optical medium, and
said nonlinear optical medium comprises an optical fiber having a zero dispersion wavelength substantially equal to the wavelength of the pump light.
11. An optical fiber communication system according to claim 1, further comprising:
an optical transmitter for supplying the signal beam to said first optical fiber; and
an optical receiver for receiving the second phase conjugate beam from said third optical fiber.
12. An optical fiber communication system according to claim 11, wherein
said optical transmitter, said first optical fiber and said first phase conjugator are included in a first terminal station while
said second phase conjugator, said third optical fiber and said optical receiver are included in a second terminal station, and
said second optical fiber is laid between said first and second terminal stations.
13. An optical fiber communication system according to claim 1, further comprising
an optical amplifier provided at said input end or said output end or intermediately of said second optical fiber for amplifying the first phase conjugate beam, whereby a loss of said second optical fiber is compensated for.
14. An optical fiber communication system according to claim 13, further comprising
an optical band-pass filter provided in the proximity of said system midpoint of said second optical fiber and having a pass-band including the wavelength of the first phase conjugate beam, whereby noise produced by said optical amplifier is removed.
15. An optical fiber communication system according to claim 13, wherein
said optical amplifier comprises a plurality of optical amplifiers.
16. An optical fiber communication system according to claim 15, wherein,
the distance between each two adjacent ones of said plurality of optical amplifiers is set shorter than the nonlinear length of said second optical fiber.
17. An optical fiber communication system according to claim 1, further comprising
a branching unit provided in the proximity of said system midpoint of said second optical fiber for branching the first phase conjugate beam into a plurality of branch beams,
each of said second portion, said second phase conjugator and said third optical fiber being provided by a plural number corresponding to the plurality of branch beams,
the plurality of branch beams being individually supplied to the plurality of second portions.
18. An optical fiber communication system according to claim 17, further comprising
means operatively connected to said branching unit for monitoring the transmission characteristic of the first phase conjugate beam.
19. An optical fiber communication system according to claim 1, wherein
said first optical fiber includes a dispersion-decreasing fiber having a chromatic dispersion which decreases as the power of the signal beam decreases, whereby the ratio between the product of the optical power and the nonlinear coefficient and the chromatic dispersion of said first optical fiber is substantially constant.
20. An optical fiber communication system according to claim 19, wherein
said dispersion-decreasing fiber comprises a plurality of dispersion shifted fibers having different chromatic dispersions from each other and connected in cascade connection.
21. An optical fiber communication system according to claim 19, further comprising
a plurality of optical amplifiers for making the optical power in said second optical fiber substantially constant.
22. An optical fiber communication system according to claim 21, wherein
said third optical fiber includes a second dispersion-decreasing fiber having a chromatic dispersion which decreases as the power of the second phase conjugate beam decreases, whereby the ratio between the product of the optical power and the nonlinear coefficient and the chromatic dispersion of said third optical fiber is substantially constant.
23. An optical fiber communication system according to claim 19, wherein
said dispersion-decreasing fiber is provided by a plural number, and said optical fiber communication system further comprises at east one optical amplifier provided between the dispersion-decreasing fibers.
24. An optical fiber communication system according to claim 1, wherein
the signal beam is a WDM signal beam obtained by wavelength division multiplexing (WDM) a plurality of signal beams having different wavelengths from each other, and
said first optical fiber is provided by a plural number corresponding to the plurality of signal beams.
25. An optical fiber communication system according to claim 24, further comprising
an optical demultiplexer operatively connected to said second phase conjugator for demultiplexing the second phase conjugate beam into a plurality of phase conjugate beams corresponding to the plurality of signal beams,
said third optical fiber being provided by a plural number corresponding to the plurality of phase conjugate beams.
26. An optical fiber communication system according to claim 1, further comprising
at least one dispersion compensator provided at the input end or the output end or intermediately of at least one of said first, second and third optical fibers for providing a chromatic dispersion of the opposite sign to that of the chromatic dispersion of each of said first, second and third optical fibers.
27. An optical fiber communication system according to claim 26, wherein
said dispersion compensator comprises a dispersion compensation fiber having a chromatic dispersion per unit length which is higher in absolute value than that of said second optical fiber.
28. An optical fiber communication system according to claim 26, wherein
each of said first, second and third optical fibers provides a normal dispersion, and
said dispersion compensator comprises a 1.3 m zero dispersion fiber.
29. An optical fiber communication system according to claim 26, wherein
said dispersion compensator comprises a fiber grating.
30. An optical fiber communication system according to claim 1, further comprising
one or more optical units each including optical elements which correspond to said first optical fiber, said first phase conjugator, said second optical fiber, said second phase conjugator and said third optical fiber,
said optical unit or units being operatively connected to said third optical fiber.
31. An optical fiber communication system, comprising:
a first optical fiber having a first end and a second end which correspond to an input end and an output end for a signal beam, respectively;
a phase conjugator operatively connected to said second end for converting the signal beam into a phase conjugate beam and outputting the phase conjugate beam;
a second optical fiber having a third end and a fourth end which correspond to an input end and an output end for the phase conjugate beam, respectively; and
at least one dispersion compensator provided on an optical path which includes said first optical fiber, said phase conjugator and said second optical fiber for providing a chromatic dispersion of the opposite sign to that of the chromatic dispersion of each of said first and second optical fibers;
the product of the average value of the chromatic dispersion and the length of said first optical fiber being substantially coincident with the product of the average value of the chromatic dispersion and the length of said second optical fiber.
32. An optical fiber communication system according to claim 31, wherein
the product of the average value of the optical power and the average value of the nonlinear coefficient in said first optical fiber and the length of said first optical fiber substantially coincides with the product of the average value of the optical power and the average value of the nonlinear coefficient in said second optical fiber and the length of said second optical fiber.
33. An optical fiber communication system according to claim 31, further comprising
a plurality of optical amplifiers provided on an optical path which includes said first optical fiber and said second optical fiber.
34. An optical fiber communication system according to claim 33, wherein
the distance between each two adjacent ones of said plurality of optical amplifiers is shorter than the nonlinear length of said optical path.
35. An optical fiber communication system according to claim 31, wherein,
when said first and second optical fibers are imaginarily divided into an equal number of intervals, the products of the average values of the chromatic dispersions and the interval lengths of each two corresponding intervals as counted from said phase conjugator substantially coincide with each other and the products of the average values of the optical powers, the average values of the nonlinear coefficients and the interval lengths of the two intervals substantially coincide with each other.
36. An optical fiber communication system according to claim 31, wherein
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first and second optical fibers at which the accumulated values of the chromatic dispersions from said phase conjugator are equal to each other substantially coincide with each other.
37. An optical fiber communication system according to claim 31, wherein
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first and second optical fibers at which the accumulated values of the products of the optical powers and the nonlinear coefficients from said phase conjugator are equal to each other substantially coincide with each other.
38. An optical fiber communication system according to claim 31, wherein
said dispersion compensator is provided intermediately of said first optical fiber.
39. An optical fiber communication system according to claim 31, wherein
said dispersion compensator is provided intermediately of said second optical fiber.
40. An optical fiber communication system according to claim 31, wherein
each of said first and second optical fibers is a single mode fiber.
41. An optical fiber communication system according to claim 40, wherein
said single mode fiber provides an anomalous dispersion in a wavelength 1.55 m band.
42. An optical fiber communication system according to claim 31, wherein
said dispersion compensator comprises a fiber grating.
43. An optical fiber communication system according to claim 31, wherein
the value of the chromatic dispersion of said dispersion compensator is set so that the waveform distortion of the phase conjugate beam at said fourth end of said second optical fiber may be minimized.
44. An optical fiber communication system according to claim 31, wherein
each of said first and second optical fibers provides a normal dispersion, and
said dispersion compensator comprises a 1.3 m zero dispersion fiber.
45. An optical fiber communication system, comprising:
a first optical fiber having a first end and a second end which correspond to an input end and an output end for a signal beam, respectively;
a phase conjugator operatively connected to said second end for converting the signal beam into a phase conjugate beam and outputting the phase conjugate beam; and
a second optical fiber having a third end and a fourth end which correspond to an input end and an output end for the phase conjugate beam, respectively;
the product of the average value of the chromatic dispersion and the length of said first optical fiber being substantially coincident with the product of the average value of the chromatic dispersion and the length of said second optical fiber;
the signal beam being a wavelength division multiplexed signal beam including a plurality of signal beams having wavelengths different from each other;
both of the second-order dispersions (dispersion gradients) of said first and second optical fibers being substantially equal to zero or having signs opposite to each other.
46. An optical fiber communication system according to claim 45, wherein
the product of the average value of the optical power and the average value of the nonlinear coefficient in said first optical fiber and the length of said first optical fiber substantially coincides with the product of the average value of the optical power and the average value of the nonlinear coefficient in said second optical fiber and the length of said second optical fiber.
47. An optical fiber communication system according to claim 45, further comprising
a plurality of optical amplifiers provided on an optical path which includes said first optical fiber and said second optical fiber.
48. An optical fiber communication system according to claim 47, wherein
the distance between each two adjacent ones of said plurality of optical amplifiers is shorter than the nonlinear length of said optical path.
49. An optical fiber communication system according to claim 45, wherein,
when said first and second optical fibers are imaginarily divided into an equal number of intervals, the products of the average values of the chromatic dispersions and the interval lengths of each two corresponding intervals as counted from said phase conjugator substantially coincide with each other and the products of the average values of the optical powers, the average values of the nonlinear coefficients and the interval lengths of the two intervals substantially coincide with each other.
50. An optical fiber communication system according to claim 45, wherein,
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first and second optical fibers at which the accumulated values of the chromatic dispersions from said phase conjugator are equal to each other substantially coincide with each other.
51. An optical fiber communication system according to claim 45, wherein,
the ratios between the products of the optical powers and the nonlinear coefficients and the chromatic dispersions at each two points on said first and second optical fibers at which the accumulated values of the products of the optical powers and the nonlinear coefficients from said phase conjugator are equal to each other substantially coincide with each other.
52. A method for producing an apparatus which has a nonlinear optical medium for generating phase conjugate light, said method comprising the steps of:
(a) cutting an optical fiber into a plurality of intervals; and
(b) re-arranging and joining together the plurality of intervals so that a conversion band in nondegenerative four wave mixing in which said nonlinear optical medium is used may be maximized to obtain said nonlinear optical medium.
53. A method according to claim 52, wherein
the step (b) includes a step of measuring the dispersion value of each of the plurality of intervals, and
the plurality of intervals are re-arranged such that those of the intervals which have comparatively low dispersion values are disposed adjacent an input end of said nonlinear optical medium when pump light is inputted to said nonlinear optical medium.
54. A method according to claim 52, wherein
at least some of the plurality of intervals are joined together such that the positive and negative signs of the dispersion values appear alternately.
55. An apparatus produced by a method according to claim 52.
56. A method for producing an apparatus which has a nonlinear optical medium for generating phase conjugate light, said method comprising the steps of:
(a) cutting an optical fiber into a plurality of intervals;
(b) measuring the dispersion value of each of the plurality of intervals; and
(c) selecting and joining together only those of the intervals which have dispersion values sufficiently low to obtain a required conversion band in nondegenerative four wave mixing in which said nonlinear optical medium is used to obtain said nonlinear optical medium.
57. An apparatus produced by a method according to claim 56.
58. A method for producing an apparatus which has a nonlinear optical medium for generating phase conjugate light, said method comprising the steps of:
(a) measuring the deviation of the zero dispersion wavelength of an optical fiber;
(b) cutting, when the deviation exceeds a range determined in advance, the optical fiber so that the cut fibers may have deviations in zero dispersion wavelength which remain within the range determined in advance; and
(c) selecting and joining together the optical fiber or the cut fibers each having a zero dispersion wavelength substantially equal to the wavelength of pump light to obtain said nonlinear optical medium.
59. An apparatus produced by a method according to claim 58.
60. An optical fiber communication system, comprising:
a plurality of optical fiber networks for WDM signal light obtained by wavelength division multiplexing (WDM) a plurality of optical signals having wavelengths different from each other; and
at least one converter for coupling said plurality of optical fiber networks to each other;
said converter including means for performing wavelength conversion and phase conjugate conversion of the plurality of optical signals collectively.
61. An optical fiber communication system according to claim 60, further comprising
an optical addingdropping apparatus for the optical signals,
said optical addingdropping apparatus being provided at a position at which the waveform distortion of the optical signals is minimized.
62. An optical fiber communication system according to claim 60, wherein
the wavelength conversion is performed between arbitrary bands included in a gain band provided by an erbium-doped fiber amplifier.
63. An optical fiber communication system according to claim 62, wherein
the arbitrary bands are a 1.55 m band and a 1.53 m band.
64. An apparatus for generating phase conjugate light, comprising:
a polarization beam splitter having first to fourth ports, said first and second ports and said third and fourth ports being coupled to each other by a first polarization plane, said first and third ports and said second and fourth ports being coupled to each other by a second polarization plane perpendicular to the first polarization plane;
a nonlinear optical medium operatively connected between said second and third ports;
a pump light source for outputting pump light; and
coupling means for supplying signal light and the pump light to said first port of said polarization beam splitter;
said coupling means including an optical coupler having first and second input ports for receiving the signal light and the pump light, respectively, and an output port, and a polarization maintaining fiber operatively connected between said output port and said first port.
65. An apparatus according to claim 64, wherein
said polarization maintaining fiber has a principal axis set so that the polarization plane of the pump light at said first port is inclined substantially by 45 degrees with respect to the first and second polarization planes.
66. An apparatus according to claim 65, wherein
said polarization maintaining fiber comprises first and second polarization maintaining fibers connected to each other by splicing, and said first and second polarization maintaining fibers have first and second principal axes which extend perpendicularly to each other.
67. An apparatus for generating phase conjugate light, comprising:
a nonlinear optical medium having a first end and a second end, said first end being supplied with signal light;
a pump light source for supplying pump light from at least one of said first end and said second end into said nonlinear optical medium; and
an optical band block filter operatively connected to said second end of said nonlinear optical medium and having a block band including the wavelength of the pump light.
68. An apparatus according to claim 67, further comprising
an optical band-pass filter operatively connected to said optical band block filter and having a pass-band including the wavelength of phase conjugate beam generated in said nonlinear optical medium.
69. An apparatus according to claim 67, further comprising
a second optical band block filter operatively connected to said first end of said nonlinear optical medium and having a block band including the wavelength of phase conjugate beam generated in said nonlinear optical medium.
70. An apparatus according to claim 67, wherein
said nonlinear optical medium includes an optical fiber.
71. An apparatus according to claim 70, wherein
said optical fiber has a zero dispersion wavelength substantially equal to the wavelength of the pump light.
72. An apparatus according to claim 70, wherein
said optical fiber has a nonlinear coefficient sufficiently high to make the length of said optical fiber short to such a degree that said optical fiber has a polarization plane maintaining capacity.
73. An apparatus according to claim 72, wherein
said optical fiber includes a core doped with GeO2 and a clad doped with fluorine.
74. An apparatus according to claim 72, wherein
said optical fiber comprises a single mode fiber, and said single mode fiber has a mode field diameter smaller than the mode field diameter of a single mode fiber which is used as a transmission line.
75. An optical transmission apparatus connected to an input end of an optical fiber transmission line, comprising:
a first optical fiber having an input end and an output end and having a chromatic dispersion amount substantially equal to a chromatic dispersion amount between a midpoint and said input end of said optical fiber transmission line;
optical signal outputting means for inputting an optical signal to said input end of said first optical fiber; and
a phase conjugator for converting the optical signal from said output end of said first optical fiber into phase conjugate light which has a phase conjugate relationship with the optical signal and inputting the phase conjugate light to said input end of said optical transmission line.
76. An optical reception apparatus connected to an output end of an optical fiber transmission line which transmits an optical signal, comprising:
a second optical fiber having an input end and an output end and having a chromatic dispersion amount substantially equal to a chromatic dispersion amount between a midpoint and said output end of said optical fiber transmission line;
a phase conjugator for converting the optical signal received from said optical fiber transmission line into phase conjugate light which has a phase conjugate relationship with the optical signal and inputting the phase conjugate light into said input end of said second optical fiber; and
a receiver for receiving the phase conjugate light from said output end of said second optical fiber.
77. An optical communication system including an optical transmission apparatus connected to an input end of an optical fiber transmission line, and an optical reception apparatus connected to an output end of said optical fiber transmission line,
said optical transmission apparatus comprising:
a first optical fiber having an input end and an output end and having a chromatic dispersion amount substantially equal to a chromatic dispersion amount between a midpoint and said input end of said optical fiber transmission line;
optical signal outputting means for inputting an optical signal to said input end of said first optical fiber; and
a first phase conjugator for converting the optical signal from said output end of said first optical fiber into first phase conjugate light which has a phase conjugate relationship with the optical signal and inputting the first phase conjugate light to said input end of said optical transmission line;
said optical reception apparatus comprising:
a second optical fiber having an input end and an output end and having a chromatic dispersion value substantially equal to a chromatic dispersion amount between said midpoint and said output end of said optical fiber transmission line;
a second phase conjugator for converting the first phase conjugate light received from said optical fiber transmission line into second phase conjugate light which has a phase conjugate relationship with the phase conjugate light and inputting the second phase conjugate light into said input end of said second optical fiber; and
a receiver for receiving the second phase conjugate light from said output end of said second optical fiber.