Claims
- 1. An optical instrument including a tunable free-space filter as a wavelength selector.
- 2. The optical instrument of claim 1, wherein the optical instrument is an optical spectrum analyzer.
- 3. The optical instrument of claim 2, wherein the optical spectrum analyzer is constructed and arranged as an optical channel monitor for wavelength-division multiplexed optical communication systems.
- 4. The optical instrument of claim 2, wherein the tunable free-space filter is a tunable thin film filter (TTFF).
- 5. The optical instrument of claim 4, wherein the TTFF is thermo-optically tunable.
- 6. The optical instrument of claim 5, wherein the tunable filter is a multi-layer film structure incorporating thin film semiconductor materials.
- 7. The optical instrument of claim 5, wherein the temperature of the TTFF is varied using an external thermal energy transfer device.
- 8. The optical instrument of claim 7, wherein the thermal energy transfer device is a resistive heating device.
- 9. The optical instrument of claim 8, wherein the resistive heating device is a ring-shaped metallic film, defining an aperture through which light passes through the filter.
- 10. The optical instrument of claim 8, wherein the resistive heating device is an optically transparent layer that is integrated with the filter in a location such that light passes through the resistive heating device.
- 11. The optical instrument of claim 10, wherein the transparent layer is a transparent conducting oxide.
- 12. The optical instrument of claim 10, wherein the transparent layer is a doped thin film selected from the list including amorphous, micro-crystalline, and polycrystalline semiconductor films.
- 13. The optical instrument of claim 10, wherein the transparent layer is a doped crystalline semiconductor.
- 14. The optical instrument of claim 4, wherein the TTFF has a single-cavity Fabry-Perot structure.
- 15. The optical instrument of claim 4, wherein the TTFF has a multi-cavity structure.
- 16. The optical instrument of claim 4, further comprising an optical detector, wherein the TTFF and the optical detector are mounted in a single hermetic package.
- 17. The optical instrument of claim 16, wherein the single hermetic package is a TO-style package.
- 18. The optical instrument of claim 16, further comprising within the single hermetic package one or more discrete temperature sensors.
- 19. The optical instrument of claim 16, further comprising within the single hermetic package one or more temperature-stabilizing devices.
- 20. The optical instrument of claim 1, wherein wavelength calibration is done automatically, further comprising an external source of one or more known wavelength signals.
- 21. The optical instrument of claim 1, wherein wavelength calibration is done automatically, further comprising an internal source of one or more known wavelength signals.
- 22. The optical instrument of claim 1, wherein wavelength calibration is done automatically, further comprising passive interferometric structures within the optical instrument that create a stable wavelength reference.
- 23. The optical instrument of claim 22, wherein the interferometric structures include a substrate of the tunable free-space filter.
- 24. The optical instrument of claim 23, wherein the interferometric structure interacts with a known light source to establish a reference signal.
- 25. The optical instrument of claim 5, further comprising a device that measures temperature of the thermo-optically tunable TTFF to determine wavelength.
- 26. The optical instrument of claim 25, wherein the device that measures the temperature is integrated with the TTFF.
- 27. The optical instrument of claim 26, the TTFF further comprising a heater layer, and wherein the heater layer further comprises the device that measures the temperature.
- 28. The optical instrument of claim 27, wherein the device that measures the temperature monitors resistance of the heater layer.
- 29. The optical instrument of claim 28, further comprising a source of a DC current to heat the heater layer and a source of a superposed AC current that is sufficient to monitor resistance of the heater layer.
- 30. The optical instrument of claim 28, further comprising four contacts to the heater layer, wherein two of the four contacts supply heater currents to edges of the heater layer and another two of the four contacts measure resistance from opposite sides of the heater layer.
- 31. The optical instrument of claim 1, further comprising a detector having an output and a signal processor connected to receive a signal from the detector output, the signal processor converting the signal received from the detector output to power v. wavelength data.
- 32. The optical instrument of claim 1, further comprising an electronics module; an optical detector; a fiber optic input; and a transistor outline (TO) package into which are mounted the tunable free-space filter, the optical detector and the fiber optic input, the TO package including pins through which electrical connections between the tunable free-space filter and the optical detector, and the electronics module are made.
- 33. The optical instrument of claim 32, further comprising a single enclosure supporting the TO package and the electronics module.
RELATED APPLICATIONS
[0001] This application claims domestic priority under 35 U.S.C. § 19(e) to provisional U.S. patent applications having serial Nos. 60/309,704, 60/310,047, 60/322,208, 60/335,175, 60/386,973 and the provisional U.S. patent application bearing attorney docket number A00770/70062, filed respectively on Aug. 2, 2001, Aug. 4, 2001, Sep. 14, 2001, Nov. 28, 2001, Jun. 6, 2002 and Jul. 9, 2002, all incorporated herein by reference.
Provisional Applications (6)
|
Number |
Date |
Country |
|
60309704 |
Aug 2001 |
US |
|
60310047 |
Aug 2001 |
US |
|
60322208 |
Sep 2001 |
US |
|
60335178 |
Nov 2001 |
US |
|
60386973 |
Jun 2002 |
US |
|
60394500 |
Jul 2002 |
US |