What is claimed is:
1. An optical waveguide device comprising:
a single-mode optical resonator waveguide serving as an optical ring resonator;
a single-mode optical inputoutput waveguide having a first end and a second end;
input signal light being inputted into the inputoutput waveguide at the first end and output signal light being outputted from the inputoutput waveguide at the second end;
the inputoutput waveguide being located close to the resonator waveguide in an area;
a mach-Zehnder interferometer formed in such a way as to include a part of the resonator waveguide as its first optical waveguide arm and a part of the inputoutput waveguide as its second optical waveguide arm in the area; and
the interferometer having a first optical coupler for optically coupling the first waveguide arm and the second waveguide arm with an input-side part of the inputoutput waveguide and a remaining part of the resonator waveguide due to multiple-mode optical interference, and a second optical coupler for optically coupling the first waveguide arm and the second waveguide arm with an output-side part of the inputoutput waveguide and the remaining part of the resonator waveguide due to multiple-mode optical interference.
2. The device according to claim 1, further comprising a temperature controller to control a temperature of at least one of the first and second waveguide arms of the interferometer, thereby controlling a phase of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the at least one of the first and second waveguide arms.
3. The device according to claim 1, further comprising a temperature controller to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide;
wherein the temperature controller is formed to overlap with the resonator waveguide.
4. The device according to claim 1, wherein the resonator waveguide is made of a material having a refractive index greater than that of a material surrounding the reactor waveguide by 4% or greater.
5. The device according to claim 1, wherein a total length of the resonator waveguide is determined in such a way that an operable frequency is 25 GHz or greater.
6. The device according to claim 1, wherein the resonator waveguide, the inputoutput waveguide, and the interferometer constitute a first optical resonator section;
and wherein at least one additional optical resonator section having a same configuration as the first resonator section is additionally provided in such a way as to be connected in cascade to the first resonator section.
7. An optical waveguide device comprising:
an optical resonator waveguide serving as an optical ring resonator;
an inputoutput optical waveguide having a first end and a second end;
input signal light being inputted into the inputoutput waveguide at the first end and output signal light being outputted from the inputoutput waveguide at the second end;
the inputoutput waveguide being located close to the resonator waveguide in an area;
a Mach-Zehnder interferometer formed in such a way as to include a part of the resonator waveguide as its first optical waveguide arm and a part of the inputoutput waveguide as its second optical waveguide arm in the area; and
the interferometer having a first optical coupler with a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs, and a second optical coupler with a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side;
and wherein an input-side part of the inputoutput waveguide and a remaining part of the resonator waveguide are optically connected to the first multiple-mode waveguide region on its second connection side while an output-side part of the inputoutput waveguide and the remaining part of the resonator waveguide are optically connected to the second multiple-mode waveguide region on its second connection side.
8. The device according to claim 7, further comprising a temperature controller to control a temperature of at least one of the first and second waveguide arms of the interferometer, thereby controlling a phase of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the at least one of the first and second waveguide arms.
9. The device according to claim 7, further comprising a temperature controller to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide;
wherein the temperature controller is formed to overlap with the resonator waveguide.
10. The device according to claim 7, wherein the resonator waveguide is made of a material having a refractive index greater than that of a material surrounding the reactor waveguide by 4% or greater.
11. The device according to claim 7, wherein a total length of the resonator waveguide is determined in such a way that an operable frequency is 25 GHz or greater.
12. The device according to claim 7, wherein the resonator waveguide, the inputoutput waveguide, and the interferometer constitute a first optical resonator section;
and wherein at least one additional optical resonator section having a same configuration as the first resonator section is additionally provided in such a way as to be connected in cascade to the first resonator section.
13. An optical waveguide device comprising:
a Mach-Zehnder interferometer including a first optical coupler, a second optical coupler, a first optical waveguide arm connecting the first coupler with the second coupler, and a second optical waveguide arm connecting the first coupler with the second coupler in such a way as to intersect the first waveguide arm;
the first coupler having a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
the second coupler having a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
an optical resonator waveguide serving as an optical ring resonator, connected in such a way that an end of the resonator waveguide is connected to the first coupler and the other end thereof is connected to the second coupler;
an optical input waveguide connected in such a way that an end of the input waveguide is connected to the first coupler; and
an optical output waveguide connected in such a way that an end of the output waveguide is connected to the second coupler;
wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side;
and wherein an end of the input waveguide is optically connected to the first multiple-mode waveguide region on its second connection side while an end of the output waveguide is optically connected to the second multiple-mode waveguide region on its second connection side.
14. The device according to claim 13, further comprising a temperature controller to control a temperature of at least one of the first and second waveguide arms of the interferometer, thereby controlling a phase of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the at least one of the first and second waveguide arms.
15. The device according to claim 13, further comprising a temperature controller to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide;
wherein the temperature controller is formed to overlap with the resonator waveguide.
16. The device according to claim 13, wherein the resonator waveguide is made of a material having a refractive index greater than that of a material surrounding the reactor waveguide by 4% or greater.
17. The device according to claim 13, wherein a total length of the resonator waveguide is determined in such a way that an operable frequency is 25 GHz or greater.
18. The device according to claim 13, wherein the resonator waveguide, the inputoutput waveguide, and the interferometer constitute a first optical resonator section;
and wherein at least one additional optical resonator section having a same configuration as the first resonator section is additionally provided in such a way as to be connected in cascade to the first resonator section.
19. An optical waveguide device comprising:
a Mach-Zehnder interferometer including a first optical coupler, a second optical coupler, a third optical coupler located between the first coupler and the second coupler, a first optical waveguide arm connecting the first coupler with the third coupler, a second optical waveguide arm connecting the first coupler with the third coupler in such a way as not to intersect the first waveguide arm, a third optical waveguide arm connecting the second coupler with the third coupler, a fourth optical waveguide arm connecting the second coupler with the third coupler in such a way as not to intersect the third waveguide arm;
the first coupler having a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
the second coupler having a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
the third coupler having a third multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
an optical resonator waveguide serving as an optical ring resonator, connected in such a way that an end of the first waveguide is connected to the first coupler and the other end thereof is connected to the second coupler;
an optical input waveguide connected in such a way that an end of the input waveguide is connected to the first coupler; and
an optical output waveguide connected in such a way that an end of the output waveguide is connected to the second coupler;
wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the third multiple-mode waveguide region on its first connection side;
and wherein an end of the third waveguide arm and an end of the fourth waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side while the other end of the third waveguide arm and the other end of the fourth waveguide arm are optically connected to the third multiple-mode waveguide region on its second connection side;
and wherein an end of the input waveguide is optically connected to the first multiple-mode waveguide region on its second connection side while an end of the output waveguide is optically connected to the second multiple-mode waveguide region on its second connection side.
20. The device according to claim 19, further comprising a temperature controller to control a temperature of at least one of the first to fourth waveguide arms of the interferometer, thereby controlling a phase of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the at least one of the first to fourth waveguide arms.
21. The device according to claim 19, further comprising a temperature controller to control a temperature of the remaining part of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide;
wherein the temperature controller is formed to overlap with the remaining part of the resonator waveguide.
22. The device according to claim 19, wherein the resonator waveguide is made of a material having a refractive index greater than that of a material surrounding the reactor waveguide by 4% or greater.
23. The device according to claim 19, wherein a total length of the resonator waveguide is determined in such a way that an operable frequency is 25 GHz of greater.
24. The device according to claim 19, wherein the resonator waveguide, the inputoutput waveguide, and the interferometer constitute a first optical resonator section;
and wherein at least one additional optical resonator section having a same configuration as the first resonator section is additionally provided in such a way as to be connected in cascade to the first resonator section.
25. A method of fabricating an optical waveguide device, comprising the steps of:
forming an under-cladding layer with a first material over a substrate;
forming a core layer on the under-cladding layer with a second material having a refractive index greater than that of the first material; and
patterning the core layer in such a way as to form a single-mode optical resonator waveguide serving as an optical ring resonator, a single-mode optical inputoutput waveguide having a first end and a second end, and a Mach-Zehnder interferometer;
wherein input signal light is inputted into the inputoutput waveguide at the first end and output signal light is outputted from the inputoutput waveguide at the second end;
and wherein the inputoutput waveguide is located close to the resonator waveguide in an area;
and wherein the interferometer is formed in such a way as to include a part of the resonator waveguide as its first optical waveguide arm and a part of the inputoutput waveguide as its second optical waveguide arm in the area;
and wherein the interferometer has a first optical coupler for optically coupling the first waveguide arm and the second waveguide arm with an input-side part of the inputoutput waveguide and a remaining part of the resonator waveguide due to multiple-mode optical interference, and a second optical coupler for optically coupling the first waveguide arm and the second waveguide arm with an output-side part of the inputoutput waveguide and the remaining part of the resonator waveguide due to multiple-mode optical interference.
26. The method according to claim 25, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with at least one of the first and second waveguide arms of the interferometer are additionally provided;
wherein the temperature controller is to control a temperature of the at least one of the first and second waveguide arms, thereby controlling a phase of signal light propagating in the interferometer.
27. The method according to claim 25, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with the resonator waveguide are additionally provided;
wherein the temperature controller is to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide.
28. A method of fabricating an optical waveguide device, comprising the steps of:
forming an under-cladding layer with a first material over a substrate;
forming a core layer on the under-cladding layer with a second material having a refractive index greater than that of the first material; and
patterning the core layer in such a way as to form an optical resonator waveguide serving as an optical ring resonator, an inputoutput optical waveguide having a first end and a second end, and a Mach-Zehnder interferometer;
wherein input signal light is inputted into the inputoutput waveguide at the first end and output signal light is outputted from the inputoutput waveguide at the second end;
and wherein the inputoutput waveguide is located close to the resonator waveguide in an area;
and wherein the Mach-Zehnder interferometer is formed in such a way as to include a part of the resonator waveguide as its first optical waveguide arm and a part of the inputoutput waveguide as its second optical waveguide arm in the area;
and wherein the interferometer has a first optical coupler with a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs, and a second optical coupler with a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side;
and wherein an input-side part of the inputoutput waveguide and a remaining part of the resonator waveguide are optically connected to the first multiple-mode waveguide region on its second connection side while an output-side part of the inputoutput waveguide and the remaining part of the resonator waveguide are optically connected to the second multiple-mode waveguide region on its second connection side.
29. The method according to claim 28, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with at least one of the first and second waveguide arms of the interferometer are additionally provided;
wherein the temperature controller is to control a temperature of the at least one of the first and second waveguide arms, thereby controlling a phase of signal light propagating in the interferometer.
30. The method according to claim 28, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with the resonator waveguide are additionally provided;
wherein the temperature controller is to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide.
31. A method of fabricating an optical waveguide device, comprising the steps of:
forming an under-cladding layer with a first material over a substrate;
forming a core layer on the under-cladding layer with a second material having a refractive index greater than that of the first material; and
patterning the core layer in such a way as to form a Mach-Zehnder interferometer, an optical resonator waveguide serving as an optical ring resonator, and an optical input waveguide, and an optical output waveguide;
wherein the interferometer includes a first optical coupler, a second optical coupler, a first optical waveguide arm connecting the first coupler with the second coupler, and a second optical waveguide arm connecting the first coupler with the second coupler in such a way as to intersect the first waveguide arm;
and wherein the first coupler has a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
and wherein the second coupler has a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
and wherein the resonator waveguide is connected in such a way that an end of the resonator waveguide is connected to the first coupler and the other end thereof is connected to the second coupler;
and wherein the input waveguide is connected in such a way that an end of the input waveguide is connected to the first coupler;
and wherein the output waveguide is connected in such a way that an end of the output waveguide is connected to the second coupler;
and wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side;
and wherein an end of the input waveguide is optically connected to the first multiple-mode waveguide region on its second connection side while an end of the output waveguide is optically connected to the second multiple-mode waveguide region on its second connection side.
32. The method according to claim 31, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with at least one of the first and second waveguide arms of the interferometer are additionally provided;
wherein the temperature controller is to control a temperature of the at least one of the first and second waveguide arms, thereby controlling a phase of signal light propagating in the interferometer.
33. The method according to claim 31, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with the resonator waveguide are additionally provided;
wherein the temperature controller is to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal propagating in the resonator waveguide.
34. A method of fabricating an optical waveguide device, comprising the steps of:
forming an under-cladding layer with a first material over a substrate;
forming a core layer on the under-cladding layer with a second material having a refractive index greater than that of the first material; and
patterning the core layer in such a way as to form a Mach-Zehnder interferometer, an optical resonator waveguide serving as an optical ring resonator, an optical input waveguide, and an optical output waveguide;
wherein the interferometer includes a first optical coupler, a second optical coupler, a third optical coupler located between the first coupler and the second coupler, a first optical waveguide arm connecting the first coupler with the third coupler, a second optical waveguide arm connecting the first coupler with the third coupler in such a way as not to intersect the first waveguide arm, a third optical waveguide arm connecting the second coupler with the third coupler, a fourth optical waveguide arm connecting the second coupler with the third coupler in such a way as not to intersect the third waveguide arm;
and wherein the first coupler has a first multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
and wherein the second coupler has a second multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
and wherein the third coupler has a third multiple-mode optical waveguide region in which multiple-mode optical interference occurs;
and wherein the resonator waveguide is connected in such a way that an end of the first waveguide is connected to the first coupler and the other end thereof is connected to the second coupler;
and wherein the input waveguide is connected in such a way that an end of the input waveguide is connected to the first coupler;
and wherein the output waveguide is connected in such a way that an end of the output waveguide is connected to the second coupler;
and wherein an end of the first waveguide arm and an end of the second waveguide arm are optically connected to the first multiple-mode waveguide region on its first connection side while the other end of the first waveguide arm and the other end of the second waveguide arm are optically connected to the third multiple-mode waveguide region on its first connection side;
and wherein an end of the third waveguide arm and an end of the fourth waveguide arm are optically connected to the second multiple-mode waveguide region on its first connection side while the other end of the third waveguide arm and the other end of the fourth waveguide arm are optically connected to the third multiple-mode waveguide region on its second connection side;
and wherein an end of the input waveguide is optically connected to the first multiple-mode waveguide region on its second connection side while an end of the output waveguide is optically connected to the second multiple-mode waveguide region on its second connection side.
35. The method according to claim 34, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with at least one of the first, second, third, and fourth waveguide arms of the interferometer;
wherein the temperature controller is to control a temperature of the at least one of the first, second, third, and fourth waveguide arms, thereby controlling a phase of signal light propagating in the interferometer.
36. The method according to claim 34, further comprising
a step of forming an upper-cladding layer to cover the patterned core layer;
a step of forming a heater layer on the upper-cladding layer; and
a step of patterning the heater layer to form a temperature controller in such a way as to overlap with the resonator waveguide are additionally provided;
wherein the temperature controller is to control a temperature of the resonator waveguide, thereby controlling a wavelength of signal light propagating in the resonator waveguide.
37. An optical waveguide device comprising:
a ring-shaped optical waveguide;
a linear optical waveguide located close to the ring-shaped waveguide with an interval;
a first optical multiple-mode interference coupler located in a part where the linear waveguide approaches the ring-shaped waveguide;
a second optical multiple-mode interference coupler located in a part where the linear waveguide approaches the ring-shaped waveguide;
wherein the first multiple-mode interference coupler and the second multiple-mode interference coupler form a Mach-Zehnder interferometer.
38. The device according to claim 37, further comprising a temperature controller for controlling a phase of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the ring-shaped waveguide in the interferometer.
39. The device according to claim 37, further comprising a temperature controller for controlling a wavelength of signal light propagating in the interferometer;
wherein the temperature controller is formed to overlap with the ring-shaped waveguide outside the interferometer.
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. A memory device comprising:
a flag cell settable between a multi bit per cell position and a single bit per cell position; and
a memory cell associated with the flag cell, the memory cell responsive to the flag cell position to provide a multi bit output when the flag cell is in the multi bit per cell position and a pseudo single bit output when the flag cell is in the single bit per cell position, the pseudo single bit output being the multi bit output masked to represent a single bit.
2. The memory device of claim 1, wherein the memory cell is a step up voltage flash cell.
3. The memory device of claim 1, wherein the flag cell is associated with a plurality of memory cells, each of the plurality of memory cells responsive to the flag cell to provide a multi bit per cell output when the flag cell is in the multi bit per cell position and a pseudo single bit per cell output when the flag cell is in the single bit per cell position.
4. The memory device of claim 1, the memory cell comprising a memory device of the group of memory devices consisting of a read only memory (ROM), an erasable programmable read only memory (EPROM), a conventional electrically erasable programmable read only memory (EEPROM), and a dynamic random access memory (DRAM).
5. The memory device of claim 1, the flag cell comprising a multi bit per cell cell of the memory device.
6. The memory device of claim 1, wherein the memory cell is a cell of an array of multi bit per cell cells.
7. The memory device of claim 1, wherein the flag cell comprises a multi bit per cell cell of an array of multi bit per cell cells.
8. The memory device of claim 1 comprising a second flag cell and a second memory cell associated with the second flag cell, the second flag cell being settable between the multi bit per cell position and the single bit per cell position, and the second memory cell associated with the second flag cell having the multi bit output when the second flag cell is in the multi bit per cell position and the pseudo single bit output when the second flag cell is in the single bit per cell position.
9. The memory device of claim 1, the memory cell having a single bit output specific voltage threshold for determining the pseudo single bit output and a count mask to overwrite the multi bit output to provide the pseudo single bit output when the flag cell is in the single bit per cell position.
10. An integrated circuit comprising the memory device of claim 1.
11. A semiconductor device comprising the memory device of claim 1.
12. The memory device of claim 1, wherein the flag cell is a memory cell of a memory array and the memory cell is another memory cell of the memory array, the flag cell being logically associated with the memory cell.
13. The memory device of claim 1, wherein the flag cell and the memory cell are logically associated.
14. A memory device comprising:
a flag cell settable between a multi bit per cell position and a single bit per cell position; and
a memory cell logically associated with the flag cell, the memory cell responsive to the flag cell position to provide a multi bit output when the flag cell is in the multi bit per cell position and a single bit output when the flag cell is in the single bit per cell position;
wherein the memory cell has a single bit output specific voltage threshold for determining the single bit output and a count mask to overwrite the multi bit output to provide the single bit output when the flag cell is in the single bit per cell position.
15. The memory device of claim 14, wherein the memory cell is a step up voltage flash cell.
16. The memory device of claim 14, wherein the flag cell is associated with a plurality of memory cells, each of the plurality of memory cells responsive to the flag cell to provide a multi bit per cell output when the flag cell is in the multi bit per cell position and a single bit per cell output when the flag cell is in the single bit per cell position.
17. The memory device of claim 14, the memory cell comprising a memory device of the group of memory devices consisting of a read only memory (ROM), an erasable programmable read only memory (EPROM), a conventional electrically erasable programmable read only memory (EEPROM), and a dynamic random access memory (DRAM).
18. The memory device of claim 14, the flag cell comprising a multi bit per cell cell of the memory device.
19. The memory device of claim 14, wherein the memory cell is a cell of an array of multi bit per cell cells.
20. The memory device of claim 14, wherein the flag cell comprises a multi bit per cell cell of an array of multi bit per cell cells.
21. The memory device of claim 14 comprising a second flag cell and a second memory cell associated with the second flag cell, the second flag cell being settable between the multi bit per cell position and the single bit per cell position, and the second memory cell associated with the second flag cell having the multi bit output when the second flag cell is in the multi bit per cell position and the single bit output when the second flag cell is in the single bit per cell position.
22. An integrated circuit comprising the memory device of claim 14.
23. A semiconductor device comprising the memory device of claim 14.