1. A light source apparatus for use with wavelength division multiplexed (WDM) optical communication comprising:
a broadband light source;
a plurality of injection light sources; and
a multiplexerdemultiplexer to (1) receive broadband light from the broadband light source, (2) provide spectrum-sliced light components to respective injection light sources, and (3) multiplex a plurality of optical signals from the injection light sources,
wherein the multiplexerdemultiplexer includes
a first waveguide to transmit the broadband light and multiplexed light with a plurality of wavelengths;
a plurality of second waveguides each to transmit light with an associated one of the wavelengths; and
a plurality of optical filters each to pass light with an associated one of the wavelengths, the pass wavelength of each optical filter being configured such that an insertion loss distribution of the optical filters at the wavelengths is similar to a gain distribution of the injection light sources at the wavelengths.
2. The light source apparatus according to claim 1, wherein the plurality of injection light sources operate at wavelengths respectively determined by external injection light inputs.
3. The light source apparatus according to claim 1, wherein the plurality of optical filters are further configured to reflect the remaining wavelengths.
4. The light source apparatus according to claim 1, wherein:
the number of the optical filters is N, and the N optical filters are connected to one another so that a downstream one of the optical filters receives light reflected from an upstream one of the optical filters directly connected to the downstream optical filter, passes light of a wavelength corresponding to the operating wavelength of the injection light source to generate an output of a power higher than the output power of the injection light source associated with the upstream optical filter, and outputs the passed light to an associated one of the second waveguides.
5. The light source apparatus according to claim 4, wherein a first one of the optical filters receives the broadband light from the broadband light source, passes light of a wavelength corresponding to the operating wavelength of the injection light source to generate an output of a lowest power, and outputs the passed light to a first one of the second waveguides; a second one of the optical filters receives light reflected by the first optical filter, passes light of a wavelength corresponding to the operating wavelength of the injection light source to generate an output of a second lower power, and outputs the passed light to a second one of the second waveguides; and an N-th one of the optical filters passes light of a wavelength corresponding to the operating wavelength of the injection light source to generate an output of a highest power, and outputs the passed light to an N-th one of the second waveguides.
6. The light source apparatus according to claim 4, wherein each of the optical filters comprises:
a third waveguide;
a fourth waveguide;
a fifth waveguide; and
a filter to filter a particular wavelength light component from multiplexed light received via the third waveguide, to output the particular wavelength light component to the fourth waveguide, to reflect the remaining light components of the multiplexed light to be outputted to the fifth waveguide, to multiplex light of a particular wavelength received from the fourth waveguide and light of another particular wavelength received from the fifth waveguide, and to output the resultant multiplexed light to the third waveguide,
wherein the third waveguide of the first optical filter is optically connected with the first waveguide, the fifth waveguide of the first optical filter is optically connected with the third waveguide of the second optical filter, and the fifth waveguide of an \u201cN\u22121\u201d-th one of the optical filters is optically connected with the third waveguide of the N-th optical filter.
7. The light source apparatus according to claim 6, wherein the filter is a thin film filter.
8. The light source apparatus according to claim 1, wherein each of the injection light sources is a Fabry-Perot laser diode (FP-LD).
9. The light source apparatus according to claim 1, wherein each of the injection light sources is a reflective semiconductor optical amplifier (R-SOA).
10. The light source apparatus according to claim 1, further comprising:
an optical circulator to transmit the broadband light from the broadband light source to the multiplexerdemultiplexer, and to transmit a multiplexed optical signal outputted from the multiplexerdemultiplexer to an optical transmission link.
11. A bi-directional wavelength division multiplexed (WDM) optical communication system comprising:
a downstream broadband light source;
a plurality of downstream injection light sources;
a central office comprising a plurality of optical filters having pass wavelengths set to compensate for a non-uniformity in a gain distribution of the downstream injection light sources, and a first optical filter multiplexerdemultiplexer to spectrum-slice the broadband light generated from the downstream broadband light source, to provide the resultant spectrum-sliced light components as the external injection light inputs for the downstream injection light sources, respectively, and to multiplex a plurality of downstream optical signals respectively generated from the downstream injection light sources;
a remote node to demultiplex a multiplexed downstream optical signal received from the central office into the downstream optical signals, and output the downstream optical signals, to multiplex a plurality of upstream optical signals inputted to the remote node, and to output the resultant multiplexed upstream optical signal to the central office; and
a plurality of optical network units to transmit, as the upstream optical signals to be multiplexed by the remote node, a plurality of upstream optical signals with different wavelengths generated from upstream external-injection light sources to the remote node, respectively, and to detect the downstream optical signals received from the remote node, respectively.
12. The WDM optical communication system according to claim 11, wherein the central office further comprises:
an upstream broadband light source to supply incoherent broadband light to the upstream external-injection light sources, respectively;
an optical splittercoupler to output, to the remote node, the upstream broadband light received from the upstream broadband light source and the multiplexed downstream optical signal received from the first optical filter multiplexerdemultiplexer, and to output the upstream optical signals received from the remote node to the first optical filter multiplexerdemultiplexer; and
a plurality of optical detectors each connected with the first optical filter multiplexerdemulitplexer to detect an associated one of the upstream optical signals, which has an associated wavelength.
13. The WDM optical communication system according to claim 12, wherein the central office further comprises:
a plurality of wavelength-selective couplers each to receive, form the first optical filter multiplexerdemultiplexer, an associated one of the upstream optical signals, which has an associated wavelength, and an associated one of the spectrum-sliced incoherent light components, which has an associated wavelength, to output the received associated upstream optical signal to an associated one of the optical detectors, to output the received associated incoherent light component to an associated one of the downstream external-injection light sources, and to output an associated one of the downstream optical signals respectively generated from the downstream external injection light sources to the first optical filter multiplexerdemultiplexer.
14. The WDM optical communication system according to claim 11, wherein the remote node comprises:
a second optical filter multiplexerdemultiplexer to demultiplex the downstream optical signals received from the central office, to multiplex the upstream optical signals respectively received from the optical network units, to output the resultant multiplexed optical signal to the central office, to spectrum-slice the upstream broadband light, and to output the resultant spectrum-sliced light components to the optical network units, respectively.
15. The WDM optical communication system according to claim 14, wherein the second optical filter multiplexerdemultiplexer comprises a plurality of optical filters to compensate for link loss caused by the first optical filter multiplexerdemultiplexer.
16. The WDM optical communication system according to claim 11, wherein each of the optical network units comprises:
an optical detector to detect an associated one of the downstream optical signals; and
a wavelength-selective coupler to output the associated downstream optical signal received from the remote node to the optical detector, to output an associated one of the spectrum-sliced incoherent light components received from the remote node to an associated one of the upstream external-injection light sources to the remote node.
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 offset printing press comprising:
a first plate cylinder;
a first blanket cylinder for selectively contacting the first plate cylinder;
an anilox inker for inking the first plate cylinder;
a first motor directly connected to the anilox inker for driving the anilox inker and connected to the first plate cylinder for driving the first plate cylinder;
a second plate cylinder;
a second blanket cylinder for selectively contacting the second plate cylinder;
a second anilox inker for inking the second plate cylinder; and
a second motor directly connected to the second anilox inker for driving the second anilox inker and connected to the second plate cylinder for driving the second plate cylinder,
further comprising a third motor for driving the first and second blanket cylinders, wherein the first and second blanket cylinders have direct gears separated from the other, with each direct gear being driven by the third motor.
2. An offset printing press comprising:
a first plate cylinder;
a first blanket cylinder for selectively contacting the first plate cylinder;
an anilox inker for inking the first plate cylinder;
a first motor directly connected to the anilox inker for driving the anilox inker and connected to the first plate cylinder for driving the first plate cylinder;
a second plate cylinder;
a second blanket cylinder for selectively contacting the second plate cylinder;
a second anilox inker for inking the second plate cylinder; and a second motor directly connected to the second anilox inker for driving the second anilox inker and connected to the second plate cylinder for driving the second plate cylinder, wherein one of the first and second motor drives the first and second blanket cylinders.
3. The press as recited in claim 2 wherein the first anilox inker includes an ink form roll and the second anilox inker a second ink form roll, and wherein in a first mode the ink form roll is driven directly by the first motor, and the first plate cylinder, first blanket cylinder and second blanket cylinder are driven indirectly by the first motor.
4. The press as recited in claim 3 wherein the second plate cylinder is thrown off of the second blanket cylinder.
5. The press as recited in claim 3 wherein in a second mode the second motor drives the second ink form roller, the second plate cylinder, and the first and second blanket cylinders.
6. The press as recited in claim 5 wherein the first plate cylinder is thrown off of the first blanket cylinder.
7. A method for driving a printing unit having a first anilox inker, a first plate cylinder, a first blanket cylinder selectively contacting the first plate cylinder, a second blanket cylinder, a second plate cylinder selectively contacting the second blanket cylinder, and a second anilox inker, the method comprising the steps of:
directly driving the first anilox inker using a first motor;
indirectly driving the first plate cylinder using the first motor;
directly driving the second anilox inker using a second motor; and indirectly driving the second plate cylinder using the second motor, including driving the first and second blanket cylinders with one of the first and second motors.