Widely tunable swept source

1. A wavelength-tunable light source operative to emit wavelength tunable radiation over a wavelength range contained in a wavelength span between about 950 nm and about 1150 nm, said wavelength tunable light source comprising a vertical cavity laser (VCL), said VCL having a gain region with at least one compressively strained quantum well containing Indium, Gallium, and Arsenic, said vertical cavity laser further comprising a first portion including a first mirror, a second portion including a second mirror attached to a mechanical structure including a flexible membrane with a support structure, an adjustable airgap between said second portion and said first portion, a first means for injecting electrons and holes into said gain region, a second means for adjusting said airgap, and a third means for obtaining substantially single longitudinal and transverse mode operation over said wavelength tuning range, wherein a peak room-temperature photoluminescence wavelength of said gain region is more than about 50 nm shorter than a maximum operating wavelength of said tunable laser.

2. The wavelength tunable light source of claim 1 , wherein a peak room-temperature photoluminescence wavelength of said gain region is more than about 70 nm shorter than a maximum operating wavelength of said tunable laser.

3. The wavelength tunable light source of claim 1 , wherein said first mirror comprises an alternating stack including a first Al(x1)Ga(1−x1)As layer and a second Al(x2)Ga(1−x2)As layer, where x1 and x2 are in a range of 0-1.

4. The wavelength tunable light source of claim 1 , where said first mirror comprises an alternating stack including a first material containing aluminum and oxygen, and a second material that is Al(x)Ga(1−x)As, where x is in a range of 0-1.

5. A wavelength-tunable light source operative to emit wavelength tunable radiation over a wavelength range contained in a wavelength span between about 950 nm and about 1150 nm, said wavelength tunable light source comprising a vertical cavity laser (VCL), said VCL having a VCL gain region with at least one compressively strained quantum well containing Indium, Gallium, and Arsenic, said vertical cavity laser further comprising a first portion including a first mirror, a second portion including a second mirror attached to a mechanical structure including a flexible membrane with a support structure, an adjustable airgap between said second portion and said first portion, a first means for injecting electrons and holes into said gain region, a second means for adjusting said airgap, a third means for obtaining substantially single longitudinal and transverse mode operation over said wavelength tuning range, said wavelength-tunable light source further comprising a semiconductor optical amplifier (SOA) comprising at least one SOA quantum well including Indium, Gallium, and Arsenic, said at least one SOA quantum well having a room temperature photoluminescence wavelength in a range of about 1050 nm-1085 nm, wherein a peak room-temperature photoluminescence wavelength of said gain region is more than about 50 nm shorter than a maximum operating wavelength of said tunable laser.

6. The wavelength tunable light source of claim 5 , wherein said semiconductor optical amplifier includes exactly one compressively strained SOA quantum well comprising Indium, Gallium, and Arsenic.

7. The wavelength tunable light source of claim 5 , wherein said semiconductor optical amplifier contains exactly 2 SOA quantum wells with at least one tensile-strained barrier.

8. The wavelength tunable light source of claim 5 , wherein said at least one SOA quantum well comprises two confined quantum states.

9. The wavelength tunable light source of claim 5 , wherein a vertical beam divergence of said semiconductor optical amplifier is less than about 25 degrees full-width at half-maximum.

10. The wavelength tunable light source of claim 5 , wherein said first mirror comprises an alternating stack including a first Al(x1)Ga(1−x1)As layer and a second Al(x2)Ga(1−x2)As layer, where x1 and x2 are in a range of 0-1.

11. The wavelength tunable light source of claim 5 , wherein said first mirror comprises an alternating stack comprising including a first material containing aluminum and oxygen, and a second material that is Al(x)Ga(1−x)As, where x is in a range of 0-1.

12. A wavelength-tunable light source operative to emit wavelength tunable radiation over a wavelength range contained in a wavelength span between about 950 nm and about 1150 nm, said wavelength tunable light source comprising a vertical cavity laser (VCL), said VCL having a gain region with at least one compressively strained quantum well containing Indium, Gallium, and Arsenic, said vertical cavity laser further comprising a first portion including a first mirror, a second portion including a second mirror attached to a mechanical structure including a flexible membrane with a support structure, an adjustable airgap between said second portion and said first portion, a first means for injecting electrons and holes into said gain region, a second means for adjusting said airgap, wherein said vertical cavity laser is surrounded by a vacuum environment which enables a substantially under-damped mechanical resonance of said mechanical structure, wherein a peak room-temperature photoluminescence wavelength of said gain region is more than about 50 nm shorter than a maximum operating wavelength of said tunable laser.

13. The wavelength tunable light source of claim 12 , wherein said vacuum environment is provided by an evacuated butterfly package.

14. The wavelength tunable light source of claim 12 , wherein said vacuum environment is provided by an evacuated transistor outline (TO) package.

15. The wavelength tunable light source of claim 12 , wherein said wavelength range is repetitively scanned at a mechanical resonant frequency of said mechanical structure.

16. The wavelength tunable light source of claim 12 , wherein said wavelength range is covered with a maximum voltage less than about 10V.

17. The wavelength tunable light source of claim 1 , wherein said VCL is driven by a periodic tuning waveform periodically adjusting said airgap, such that said wavelength tunable radiation has a periodic wavelength variation with time at a first wavelength repetition frequency and a first repetition period, further comprising at least one optical delay line for generating at least one time-delayed copy of said wavelength tunable radiation, a combiner for combining all of said time-delayed copies into a common optical path to create a multiplexed wavelength-swept radiation, and a fifth means for turning off said VCL during a time window of said first wavelength repetition period, wherein said multiplexed wavelength swept radiation has a second wavelength repetition frequency which is an integer multiple of said first wavelength repetition frequency.

18. A system for optical coherence tomography, the system comprising at least one wavelength tunable light source of claim 1 , wherein said VCL is driven by a periodic tuning waveform which periodically adjusts said airgap such that said wavelength-tunable radiation is repetitively tuned over said wavelength range, a splitter for splitting said wavelength tunable radiation to a sample and a reference path, an optical detector for detecting an interference signal between a reflection from said sample and light traversing said reference path, and a signal processing system for constructing an image from said interference signal.

19. The system of claim 18 , wherein said sample is an in-vivo human eye.

20. The system of claim 19 , wherein said image includes a portion of both the anterior eye and the retina.

21. The system of claim 18 , wherein a dynamic coherence length of said wavelength-swept radiation exceeds 100 mm.

22. A system for optical coherence tomography, the system comprising at least one wavelength tunable light source of claim 5 , wherein said VCL is driven by a periodic tuning waveform which periodically adjusts said airgap such that said wavelength-tunable radiation is repetitively tuned over said wavelength range, a splitter for splitting said wavelength tunable radiation to a sample and a reference path, an optical detector for detecting an interference signal between a reflection from said sample and light traversing said reference path, and a signal processing system for constructing an image from said interference signal.

23. The system of claim 22 , wherein said sample is an in-vivo human eye.

24. The system of claim 23 , wherein said image includes a portion of both the anterior eye and the retina.

25. The system of claim 22 , wherein a dynamic coherence length of said wavelength-swept radiation exceeds 100 mm.

26. A system for optical coherence tomography, the system comprising at least one wavelength tunable light source of claim 12 , wherein said VCL is driven by a periodic tuning waveform which periodically adjusts said airgap such that said wavelength-tunable radiation is repetitively tuned over said wavelength range, a splitter for splitting said wavelength tunable radiation to a sample and a reference path, an optical detector for detecting an interference signal between a reflection from said sample and light traversing said reference path, and a signal processing system for constructing an image from said interference signal.

27. The system of claim 26 , wherein said sample is an in-vivo human eye.

28. The system of claim 27 , wherein said image includes a portion of both the anterior eye and the retina.

29. The system of claim 26 , wherein a dynamic coherence length of said wavelength-swept radiation exceeds 100 mm.

30. The wavelength tunable light source of claim 5 , wherein a thickness of said at least one SOA quantum well is in a range of about 5-10 nm.