Infrared laser

• US 8,885,676 B2
• Filed: 11/14/2012
• Issued: 11/11/2014
• Est. Priority Date: 11/14/2011
• Status: Active Grant

• Current Assignee: USA As Represented By Thesecretary of The Navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Kub, Francis J., Currie, Marc
• Primary Examiner(s): Matthews, Celleen A
• Assistant Examiner(s): NGUYEN, TUAN N
• Application Number:
  US13/676,608
• Publication Number:
  US 20130121362A1
• Time in Patent Office: 727 Days
• Field of Search: 372/50.22, 372/50.124, 372/50.23
• US Class Current: 372/22
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01S 3/06 Construction or shape of active medium
• CPC Class Codes: H01S 3/081 comprising three or more reflectors
• CPC Class Codes: H01S 3/0813 Configuration of resonator
• CPC Class Codes: H01S 3/0815 having 3 reflectors, e.g. V-shaped resonators
• CPC Class Codes: H01S 3/083 Ring lasers fibre ring lasers H01S3/06791
• CPC Class Codes: H01S 3/0906 Electrical, electrochemical, or electron-beam pumping of a dye laser
• CPC Class Codes: H01S 3/091 using optical pumping
• CPC Class Codes: H01S 3/10 Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
• CPC Class Codes: H01S 3/1106 Mode locking
• CPC Class Codes: H01S 3/1112 Passive mode locking
• CPC Class Codes: H01S 3/1115 using intracavity saturable absorbers
• CPC Class Codes: H01S 3/1118 Semiconductor saturable absorbers, e.g. semiconductor saturable absorber mirrors [SESAMs]; Solid-state saturable absorbers, e.g. carbon nanotube [CNT] based
• CPC Class Codes: H01S 3/113 using intracavity saturable absorbers
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
• CPC Class Codes: H01S 5/0601 comprising an absorbing region H01S5/0604, H01S5/0607, H01S5/0615 and H01S5/065 take precedence; bistable laser devices in general G02F3/026
• CPC Class Codes: H01S 5/10 Construction or shape of the optical resonator , e.g. extended or external cavity, coupled cavities, bent-guide, varying width, thickness or composition of the active region H01S5/20 takes precedence
• CPC Class Codes: H01S 5/1032 Coupling to elements comprising an optical axis that is not aligned with the optical axis of the active region
• CPC Class Codes: H01S 5/14 External cavity lasers H01S5/18 takes precedence; mode locking H01S5/065
• CPC Class Codes: H01S 5/1838 Reflector bonded by wafer fusion or by an intermediate compound
• CPC Class Codes: H01S 5/3401 : having no PN junction, e.g. unipolar lasers, intersubband lasers, quantum cascade lasers
• CPC Class Codes: H01S 5/50 : Amplifier structures not provided for in groups H01S5/02 - H01S5/30

Abstract

Laser devices are presented in which a graphene saturable absorber and an optical amplifier are disposed in a resonant optical cavity with an optical or electrical pump providing energy to the optical amplifier.

Claims

1. A laser device, comprising:

a first mirror with a first surface;

a second mirror with a second surface at least partially facing the first surface of the first mirror, the first and second mirrors defining a resonant optical cavity in which electromagnetic energy is amplified by stimulated emission of coherent radiation that is partially transmitted through the second mirror;

a semiconductor optical amplifier disposed at least partially between the first and second surfaces;

wherein the semiconductor optical amplifier gain exceeds the loss within the resonant optical cavity over a broad spectral bandwidth;

an electrical or optical pump providing energy to the semiconductor optical amplifier; and

a graphene saturable absorber disposed at least partially between the first and second surfaces;

wherein the graphene saturable absorber operates in a passive mode;

wherein the laser device emits stimulated coherent radiation through the second mirror with center wavelengths of about 1,800 nm or more and about 25,000 nm or less; and

has a spectral width of about 0.006% or more of a center wavelength.

2. The laser device of claim 1, wherein the laser device is a mode-locked laser or a Q-switched laser configured to emit stimulated coherent radiation through the second mirror with center wavelengths of about 280 nm or more and about 1,800 nm or less.

3. The laser device of claim 1, wherein the semiconductor optical amplifier comprises a superlattice of alternating semiconductor layers of at least two different material compositions.

4. The laser device of claim 1, wherein the graphene saturable absorber is disposed between the first surface and the semiconductor optical amplifier.

5. The laser device of claim 4, wherein the semiconductor optical amplifier comprises opposite first and second ends, and wherein the graphene saturable absorber is integral with the first end of the semiconductor optical amplifier.

6. The laser device of claim 5, wherein the second mirror is integral with the second end of the semiconductor optical amplifier.

7. The laser device of claim 6, wherein the second mirror is a partially reflective facet on the second end of the semiconductor optical amplifier.

8. The laser device of claim 6, wherein the second mirror is a partially reflective coating on the second end of the semiconductor optical amplifier.

9. The laser device of claim 5, wherein the second mirror is spaced from the second end of the semiconductor optical amplifier.

10. The laser device of claim 9, wherein the second mirror is a Bragg mirror.

11. The laser device of claim 9, further comprising at least one optical component disposed between the second end of the semiconductor optical amplifier and the second mirror.

12. The laser device of claim 11, wherein the at least one optical component is a gas cell.

13. The laser device of claim 4, wherein the graphene saturable absorber is integral to the first mirror.

14. The laser device of claim 13, wherein the first mirror is formed as a highly reflective coating on the graphene saturable absorber.

15. The laser device of claim 13, wherein the first mirror is a Bragg mirror or a highly reflective coating on a substrate.

16. The laser device of claim 4, wherein the graphene saturable absorber is spaced from the semiconductor optical amplifier.

17. The laser device of claim 16, wherein the graphene saturable absorber is integral to the first mirror.

18. The laser device of claim 16, further comprising at least one optical component disposed between the first end of the semiconductor optical amplifier and the graphene saturable absorber.

19. The laser device of claim 18, wherein the at least one optical component is a gas cell.

20. The laser device of claim 16, further comprising at least one optical component disposed between the second end of the semiconductor optical amplifier and the second mirror.

21. The laser device of claim 20, wherein the at least one optical component is a gas cell.

22. The laser device of claim 4, wherein the graphene saturable absorber is spaced from the first mirror, further comprising at least one optical component disposed between the graphene saturable absorber and the first mirror.

23. The laser device of claim 22, wherein the at least one optical component is a gas cell.

24. The laser device of claim 22, wherein the graphene saturable absorber is integral with the semiconductor optical amplifier.

25. The laser device of claim 1, wherein the semiconductor optical amplifier is a quantum cascade semiconductor optical amplifier.

26. The laser device of claim 1, wherein the semiconductor optical amplifier is an interband cascade.

27. The laser device of claim 1, wherein the laser device is a frequency comb laser.

28. The laser device of claim 1, wherein the laser device is a mode-locked laser or a Q-switched laser configured to emit stimulated coherent radiation through the second mirror and having a spectral width of about 10% of a center wavelength.

29. The laser device of claim 1, wherein the laser device is a linear cavity or external cavity mode-locked laser or a Q-switched laser configured to emit stimulated coherent radiation through the second mirror.

30. The laser device of claim 1, having a spectral width of about 0.5% or more of a center wavelength.

31. The laser device of claim 30, having a spectral width of about 2.0% or more of the center wavelength.

32. The laser device of claim 31, having a spectral width of about 10.0% or less of the center wavelength.