1. A tunable laser comprising:
a. an optical cavity comprising a first and second mirror;
b. a gain medium positioned in the optical cavity;
c. a thermally tunable optical filter comprising an integrated resistive heater positioned in the optical cavity, the thermally tunable optical filter being heated to a temperature that selects a desired optical mode of the optical cavity; and
d. a thermally tunable optical phase retarder comprising an integrated resistive heater positioned in the optical cavity, the thermally tunable optical phase retarder being heated to a temperature that changes an optical path length in the optical cavity, independent of the physical cavity length, by an amount corresponding to a resonant frequency of the tunable optical filter so that a phase-matching condition of the optical cavity is shifted to the desired optical mode of the optical cavity selected by the thermally tunable optical filter.
2. The tunable laser of claim 1 wherein the gain medium positioned in the optical cavity comprises a semiconductor gain medium.
3. The tunable laser of claim 1 wherein the thermally tunable filter comprises a thermally tunable Fabry-Perot optical filter.
4. The tunable laser of claim 1 wherein the thermally tunable filter comprise a tunable Fabry-Perot optical filter comprising a single crystalline sheet resistance heater layer and distributed Bragg reflectors.
5. The tunable laser of claim 1 wherein at least one of the integrated resistive heater of the thermally tunable optical filter and the integrated resistive heater of the thermally tunable optical phase retarder comprises a single crystalline sheet resistive heater.
6. The tunable laser of claim 1 wherein the thermally tunable filter comprises a tuning range wide enough to selectively pass signals in an entire optical communications transmission band.
7. The tunable laser of claim 1 wherein the thermally tunable filter comprises a tuning range wide enough to selectively pass signals in one of the C- or L-bands.
8. The tunable laser of claim 1 wherein the thermally tunable filter comprises an integrated thermistor.
9. The tunable laser of claim 1 wherein the thermally tunable filter is selected from the group comprising a single-crystalline silicon cavity, an amorphous silicon cavity, and a III-IV semiconductor Fabry-Perot cavity.
10. The tunable laser of claim 1 wherein the thermally tunable filter device and the thermally tunable optical phase retarder are physically integrated into a single device.
11. The tunable laser of claim 1 wherein the thermally tunable optical phase retarder changes a phase by more than one-half of a wavelength of an optical beam propagating in the optical cavity.
12. A tunable laser comprising:
a. an optical cavity comprising a mirror at one end and a laser facet at the other end;
b. a semiconductor gain medium comprising the laser facet at one end and having an antireflection coating at the other end, the semiconductor gain medium being positioned in the optical cavity;
c. a thermally tunable optical filter comprising an integrated resistive heater positioned in the optical cavity, the thermally tunable optical filter being heated to a temperature that selects a desired optical mode of the optical cavity; and
d. a thermally tunable optical phase retarder comprising an integrated resistive heater positioned in the optical cavity, the thermally tunable optical phase retarder being heated to a temperature that changes an optical path length in the optical cavity, independent of the physical cavity length, by an amount corresponding to a resonant frequency of the tunable optical filter so that a phase-matching condition of the optical cavity is shifted to the desired optical mode of the optical cavity selected by the thermally tunable optical filter.
13. The tunable laser of claim 12 wherein the thermally tunable filter comprises a tunable Fabry-Perot optical filter comprising a single crystalline sheet resistance heater layer and distributed Bragg reflectors.
14. The tunable laser of claim 12 wherein the thermally tunable filter device and the thermally tunable optical phase retarder are physically integrated in a single device.
15. The tunable laser of claim 12 wherein at least one of the thermally tunable filter device and the thermally tunable optical phase retarder comprises an integrated thermistor.
16. A method of tuning a laser, the method comprising:
a. forming an optical cavity comprising a first and second mirror;
b. generating stimulated emission in the optical cavity;
c. adjusting a temperature of a thermally tunable optical filter with an integrated resistive heater positioned in the optical cavity to select a desired optical mode of the optical cavity; and
d. adjusting a temperature of a thermally tunable optical phase retarder comprising an integrated resistive heater positioned in the optical cavity to change an optical path length in the optical cavity, independent of the physical cavity length, by an amount corresponding to a resonant frequency of the tunable optical filter so that a phase-matching condition of the optical cavity is shifted to the desired optical mode of the optical cavity selected by the thermally tunable optical filter.
17. The method of claim 16 wherein the adjusting the temperature of the thermally tunable optical filter comprising applying a current to the integrative resistive heater of the thermally tunable optical filter.
18. The method of claim 16 wherein the adjusting the temperature of the thermally tunable optical phase retarder comprising applying a current to the integrative resistive heater of the thermally tunable optical phase retarder.
19. The method of claim 16 further comprising aligning at least one of the first mirror, the second mirror, the thermally tunable optical filter, and the thermally tunable optical phase retarder to improve performance.
20. The method of claim 16 further comprising measuring a temperature of the thermally tunable optical filter.
21. The method of claim 16 further comprising calibrating a filter response of the thermally tunable optical filter as a function of temperature.
22. The method of claim 16 further comprising measuring a temperature of the thermally tunable optical phase retarder.
23. The method of claim 16 further comprising calibrating a phase retardation response of the thermally tunable optical phase retarder as a function of temperature.
24. The method of claim 16 wherein the adjusting the temperature of the thermally tunable optical phase retarder changes a phase by more than one-half of a wavelength of an optical beam propagating in the optical cavity.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A power supply apparatus connected to a load circuit comprising:
a battery charging controller that is connected to a battery and charges this battery at a first voltage; and
a diagnosing circuit for diagnosing a deterioration of said battery in accordance with a voltage of said battery,
wherein an electric power is supplied to said load circuit from said battery or said battery charging controller.
2. A power supply apparatus connected to a load circuit comprising:
a battery charging controller that is connected to a battery and charges said battery at a first voltage; and
a voltage controller that is connected to said load circuit and generates a second voltage and then controls the second voltage so as to supply a constant voltage to said load circuit,
wherein an electric power is supplied to said load circuit from at least one of said battery, said battery charging controller and said voltage controller.
3. A power supply apparatus connected to a load circuit comprising:
a battery charging controller that is connected to a battery and charges said battery at a first voltage;
a voltage controller that is connected to said load circuit and generates a second voltage and then controls the second voltage so as to supply a constant voltage to said load circuit; and
a diagnosing circuit for diagnosing a deterioration of this battery in accordance with a voltage of said battery,
wherein an electric power is supplied to said load circuit from at least one of said battery, said battery charging controller and said voltage controller.
4. A power supply apparatus according to claim 1, further comprising an inserting unit for inserting a dummy load into said load circuit in series so as to supply a constant current to said load circuit.
5. A power supply apparatus according to claim 4, further comprising a current measuring circuit for measuring a value of a current supplied from said battery or said battery charging controller, and controlling said inserting unit so as to insert said dummy load into said load circuit in series, on the basis of measured said current value and a set current value.
6. A power supply apparatus according to claim 1,
wherein said battery charging controller receives an alternating voltage and generates said first voltage,
said diagnosing circuit, when an input of said alternating voltage is stopped during a diagnosis of a deterioration of said battery, stops the diagnosis of the deterioration of said battery, and
an electric power is supplied to said load circuit from said battery or said battery charging controller.
7. A power supply apparatus according to claim 1,
wherein said diagnosing circuit outputs a predetermined charging control signal to said battery charging controller, and
said battery charging controller charges said battery in response to said charging control signal.
8. A power supply apparatus according to claim 1, wherein said diagnosing circuit compares said battery voltage with a set voltage, and diagnoses a deterioration of said battery in accordance with the compared result.
9. A power supply apparatus according to claim 1, further comprising an electrical reception monitor for monitoring an electrical reception condition of an alternating voltage, and outputting an electrical reception signal to said diagnosing circuit,
wherein said battery charging controller receives said alternating voltage and generates said first voltage, and
said diagnosing circuit stops or resumes a diagnosis of a deterioration of said battery, in response to said electrical reception signal.
10. A power supply apparatus according to claim 9, further comprising a period setting circuit for setting a set period,
wherein said diagnosing circuit, when the electrical reception of said alternating voltage is stopped in said set period set by said period setting circuit, stops the diagnosis of the deterioration of said battery, and when the electrical reception of said alternating voltage is recovered, resumes the diagnosis of the deterioration of said battery.
11. A method of diagnosing a deterioration of a battery, in a power supply apparatus connected to a load circuit, comprising the steps of:
(a) charging said battery at a first voltage;
(b) setting a set voltage;
(c) comparing a battery voltage with said set voltage;
(d) diagnosing the deterioration of said battery in accordance with a result compared at said step (c); and
(e) supplying the battery voltage or the first voltage to said load circuit.
12. A method of diagnosing a deterioration of a battery, in a power supply apparatus connected to a load circuit, comprising the steps of:
(a) charging said battery at a first voltage;
(b) setting a set voltage;
(c) comparing a battery voltage with said set voltage;
(d) diagnosing the deterioration of said battery in accordance with a result compared at said step (c);
(f) generating a second voltage, and controlling the second voltage so as to supply a constant voltage to said load circuit; and
(g) supplying at least one voltage of the battery voltage, the first voltage and the second voltage to said load circuit.
13. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 11, further comprising the step of:
(h) inserting a dummy load into said load circuit in series so as to supply a constant current to said load circuit.
14. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 12, further comprising the step of:
(h) inserting a dummy load into said load circuit in series so as to make a current supplied to said load circuit constant.
15. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 13, further comprising the steps of:
(i) setting a set current;
(j) measuring a value of a current supplied from said battery or a current corresponding to said second voltage; and
(k) inserting said dummy load into said load circuit in series, on the basis of said set current and said value measured at said step (j).
16. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 14, further comprising the steps of:
(i) setting a set current;
(j) measuring a value of a current supplied from said battery or a current corresponding to said second voltage; and
(k) inserting said dummy load into said load circuit in series, on the basis of said set current and said value measured at said step (j).
17. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 11, further comprising the steps of:
(l) setting a set period;
(m) executing said step (c) and said step (d) at a time of an elapse of said set period;
(n) receiving an alternating voltage;
(o) monitoring an electrical reception of said alternating voltage, in accordance with said set period;
(p) stopping said step (c) and said step (d) when the electrical reception of said alternating voltage is stopped; and
(q) resuming said step (c) and said step (d) when the electrical reception of said alternating voltage is recovered.
18. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 12, further comprising the steps of:
(l) setting a set period;
(m) executing said step (c) and said step (d) at a time of an elapse of said set period;
(n) receiving an alternating voltage;
(o) monitoring an electrical reception of said alternating voltage, in accordance with said set period;
(p) stopping said step (c) and said step (d) when the electrical reception of said alternating voltage is stopped; and
(q) resuming said step (c) and said step (d) when the electrical reception of said alternating voltage is recovered
19. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 11, further comprising the steps of:
(r) stopping said step (c) and step (d) when said battery is diagnosed as a deterioration at said step (d) and
(s) resuming said step (c) and said step (d) when said battery diagnosed as said deterioration is recovered.
20. A method of diagnosing a deterioration of a battery, in a power supply apparatus according to claim 12, further comprising the steps of:
(r) stopping said step (c) and step (d) when said battery is diagnosed as a deterioration at said step (d); and
(s) resuming said step (c) and said step (d) if said battery diagnosed as said deterioration is recovered.