Widely tunable infrared source system and method

• US 9,865,985 B1
• Filed: 06/20/2013
• Issued: 01/09/2018
• Est. Priority Date: 06/20/2012
• Status: Active Grant

• Current Assignee: Panasonic Corporation Of North America (Panasonic Holdings Corporation)
• Original Assignee: TeraDiode, Inc. (Panasonic Holdings Corporation)
• Inventors: Chann, Bien, Huang, Robin, Tayebati, Parviz
• Primary Examiner(s): Vu, Vu A
• Application Number:
  US13/923,344
• Time in Patent Office: 1,664 Days
• Field of Search: 372 20
• CPC Class Codes: B01L 2200/147 Employing temperature sensors
• CPC Class Codes: B01L 2300/046 Function or devices integrated in the closure
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0851 Bottom walls
• CPC Class Codes: B01L 3/50851 specially adapted for heating or cooling samples laboratory heating apparatus B01L7/00; incubators C12M
• CPC Class Codes: G01N 1/31 Apparatus therefor
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples
• CPC Class Codes: H01S 2301/20 Lasers with a special output beam profile or cross-section, e.g. non-Gaussian
• CPC Class Codes: H01S 3/0085 Modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 3/0635 provided with a periodic structure, e.g. using distributed feed-back, grating couplers controlling, e.g. modulating distributed feed-back lasers H01S3/102
• CPC Class Codes: H01S 3/08009 using a diffraction grating
• CPC Class Codes: H01S 3/0812 using a diffraction grating
• 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 3/10023 by functional association of additional optical elements, e.g. filters, gratings, reflectors
• CPC Class Codes: H01S 3/101 Lasers provided with means to change the location from which, or the direction in which, laser radiation is emitted
• CPC Class Codes: H01S 3/105 by controlling the mutual position or the reflecting properties of the reflectors of the cavity , e.g. by controlling the cavity lengthH01S3/10076, H01S3/13 take precedence
• CPC Class Codes: H01S 3/1055 one of the reflectors being constituted by a diffraction grating
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0071 for beam steering, e.g. using a mirror outside the cavity to change the beam direction
• CPC Class Codes: H01S 5/0085 for modulating the output, i.e. the laser beam is modulated outside the laser cavity
• CPC Class Codes: H01S 5/02253 : using lenses
• CPC Class Codes: H01S 5/02255 : using beam deflecting elements
• CPC Class Codes: H01S 5/02325 : Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/06253 : Pulse modulation
• CPC Class Codes: H01S 5/141 : using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence
• CPC Class Codes: H01S 5/143 : Littman-Metcalf configuration, e.g. laser - grating - mirror
• CPC Class Codes: H01S 5/3401 : having no PN junction, e.g. unipolar lasers, intersubband lasers, quantum cascade lasers
• CPC Class Codes: H01S 5/4012 : Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4062 : with an external cavity or using internal filters, e.g. Talbot filters
• CPC Class Codes: H01S 5/4087 : emitting more than one wavelength
• CPC Class Codes: H01S 5/423 : having a vertical cavity

Abstract

A system and method for tuning and infrared source laser in the Mid-IR wavelength range. The system and method comprising, at least, a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength, a grating, a mirror positioned after the grating to receive at least one refracted order of light of at least one beam and to redirect the beam back towards the grating, and a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors.

Claims

1. A tunable IR source comprising:

a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength;

a grating;

a first optical element positioned to receive the beams and cause the beams to converge onto the grating;

a first mirror positioned to receive at least one refracted order of the beams transmitted by the grating and to redirect the refracted order back towards the grating;

a micro-electro-mechanical systems (MEMS) device containing a plurality of adjustable micro-mirrors;

a second optical element configured to receive a portion of the beams transmitted by the grating and direct the beams onto at least one micro-mirror of the MEMS device, wherein at least one beam (i) is reflected by the at least one micro-mirror and back towards the grating, thereby forming one or more tuned beams, and (ii) does not propagate to the first optical element after being reflected by the at least one micro-mirror; and

a third optical element configured to collimate transmitted tuned beams from the grating.

2. The tunable IR source of claim 1, wherein the individually tunable emitters are quantum cascade laser sources.

3. The tunable IR source of claim 2, wherein at least forty quantum cascade laser sources are used.

4. The tunable IR source of claim 2, wherein the quantum cascade laser sources are single emitter, single traverse mode semiconductor cascade laser sources.

5. The tunable IR source of claim 1, wherein at least twenty individually tunable emitters are used.

6. The tunable IR source of claim 1, wherein the unique wavelengths of the beams emitted have a gain peak ranging from about 5.9 micrometers to about 10.1 micrometers.

7. The tunable IR source of claim 1, wherein the gain peak of the unique wavelength of one individually tunable emitter is at least 0.2 micrometers different than any adjacent individually tunable emitter.

8. The tunable IR source of claim 1, wherein the individually tunable emitters each have a tuning range of about 100 nanometers to about 200 nanometers.

9. The tunable IR source of claim of claim 1, wherein each individually tunable emitter is comprised of a gain medium positioned between a reflective back surface and a partially-reflecting front surface.

10. The tunable IR source of claim 1, wherein the micro-electro-mechanical systems device is a digital light processing chip.

11. The tunable IR source of claim 1, wherein the micro-electro-mechanical systems device contains up to 100 adjustable micro-mirrors.

12. The tunable IR source of claim 1, wherein the micro-electro-mechanical systems device has a tuning step time of less than about 125 microseconds.

13. The tunable IR source of claim 1, wherein the micro-electro-mechanical systems device has a tuning step time of less than about 10 microseconds.

14. The tunable IR source of claim 1, wherein the grating has a dispersion of at least 150 lines per millimeter.

15. The tunable IR source of claim 1, wherein the grating is a diffraction grating.

16. The tunable IR source of claim 14, wherein the grating is a transmission grating.

17. The tunable IR source of claim 1, wherein the total optical bandwidth of the source is about 4000 nanometers.

18. A method for tuning an IR source, comprising the steps of:

arranging a plurality of individually tunable emitters into an array, each emitter emitting a beam having a unique wavelength;

converging the emitted beam onto a grating using a first optical element positioned to receive at least one beam from the emitters;

transmitting portions of the beam from the grating to both a mirror and a second optical element;

reflecting the portion of the beam from the mirror back towards the grating;

directing the portion of the beam through the second optical element and onto at least one micro-mirror of a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors to thereby form one or more tuned beams;

redirecting at least one tuned beam from the micro-mirrors back to the grating, wherein the at least one tuned beam does not propagate to the first optical element after being redirected from the micro-mirrors; and

collimating transmitted tuned beams from the grating using a third optical element.

19. The method of claim 18, wherein the micro-electro-mechanical systems device is a digital light processing chip.