Tunable laser array system

• US 9,696,132 B2
• Filed: 03/14/2014
• Issued: 07/04/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Praevium Research, Inc., Thorlabs Incorporated
• Original Assignee: Praevium Research, Inc., Thorlabs Incorporated
• Inventors: Jayaraman, Vijaysekhar, Cable, Alex Ezra, Burgner, Christopher, John, Demis, Potsaid, Benjamin Michael
• Primary Examiner(s): Pinkney, Dawayne A
• Application Number:
  US14/214,425
• Publication Number:
  US 20140268050A1
• Time in Patent Office: 1,208 Days
• Field of Search: 351206, 351200, 351205, 351208-210, 351221, 351243, 351246
• CPC Class Codes: A61B 3/0008 provided with illuminating means A61B3/117 takes precedence; goniolenses used for laser treatment A61F9/009; illuminating means for optical instruments G02B27/00
• CPC Class Codes: A61B 3/102 for optical coherence tomography [OCT]
• CPC Class Codes: G01B 9/02004 using frequency scans
• CPC Class Codes: G01B 9/02007 Two or more frequencies or sources used for interferometric measurement using only beat G01B9/02003
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: H01S 5/0607 by varying physical parameters other than the potential of the electrodes, e.g. by an electric or magnetic field, mechanical deformation, pressure, light, temperature
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18366 Membrane DBR, i.e. a movable DBR on top of the VCSEL
• CPC Class Codes: H01S 5/18369 based on dielectric materials
• CPC Class Codes: H01S 5/18372 by native oxidation
• CPC Class Codes: H01S 5/18377 comprising layers of different kind of materials, e.g. combinations of semiconducting with dielectric or metallic layers
• CPC Class Codes: H01S 5/2059 by means of particular conductivity zones, e.g. obtained by particle bombardment or diffusion
• CPC Class Codes: H01S 5/3095 Tunnel junction
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

A system for swept source optical coherence tomography, the system including a light source emitting multiplexed wavelength-swept radiation over a total wavelength range, the light source including N wavelength-swept vertical cavity lasers (VCL) emitting N tunable VCL outputs having N wavelength trajectories, a combiner for combining the N tunable VCL optical outputs into a common optical path to create the multiplexed wavelength-swept radiation, a splitter for splitting the multiplexed wavelength-swept radiation to a sample and a reference path, an optical detector for detecting an interference signal created by an optical interference between a reflection from the sample and light traversing the reference path, and a signal processing system which uses the interference signal to construct an image of the sample, wherein at least one of the N wavelength trajectories differs from another of the N wavelength trajectories with respect to at least one parameter.

Claims

1. A system for swept source optical coherence tomography, the system comprising a light source emitting multiplexed wavelength-swept radiation over a total wavelength range, said light source comprising N wavelength-swept vertical cavity lasers (VCL) emitting N tunable VCL outputs having N wavelength trajectories, where N is greater than one, a combiner for combining said N tunable VCL optical outputs into a common optical path to create said multiplexed wavelength-swept radiation, a splitter for splitting said multiplexed wavelength-swept radiation to a sample and a reference path, an optical detector for detecting an interference signal created by an optical interference between a reflection from said sample and light traversing said reference path, and a signal processing system which uses said interference signal to construct an image of said sample, wherein at least one of said N wavelength trajectories differs substantially from another of said N wavelength trajectories with respect to at least one parameter of the group consisting of wavelength repetition rate, wavelength sweep speed, phase translation, and wavelength tuning range, wherein said N vertical cavity lasers include a first VCL emitting a first VCL output over a first VCL wavelength tuning range, and a second VCL emitting a second VCL output over a second VCL wavelength tuning range, wherein said total wavelength range comprises a combination of said first and second VCL wavelength tuning ranges.

2. The system of claim 1, wherein each of said N VCLs is electrically pumped.

3. The system of claim 1, wherein each of said N VCLs is optically pumped.

4. The system of claim 1, wherein each of said N VCLs has an integrated VCL optical pump.

5. The system of claim 3, wherein a single optical pump is used to pump all of said N VCLs.

6. The system of claim 1, wherein a single optical amplifier is used to amplify said wavelength swept radiation.

7. The system of claim 1, wherein each VCL is monolithically integrated with an optical amplifier.

8. The system of claim 1, wherein all of said N vertical cavity lasers are monolithically integrated on a common substrate.

9. The system of claim 1, wherein at least one of said N vertical cavity lasers is a microelectromechanical systems (MEMS)-tunable VCL tuned by a voltage source.

10. The system of claim 1, wherein every one of said N vertical cavity lasers is a MEMS-tunable VCL tuned by a voltage source.

11. The system of claim 1, wherein exactly one of said N VCL tunable outputs is turned on at any one point in time.

12. The system of claim 11, wherein each of said N vertical cavity lasers is electrically pumped, and each of said N VCL outputs is turned on and off by control of an electrical pumping drive current.

13. The system of claim 1, wherein each of said N vertical cavity lasers is repetitively swept at a different wavelength repetition rate.

14. The system of claim 1, wherein each of said N vertical cavity lasers is swept over a different wavelength bandwidth.

15. The system of claim 14, wherein a VCL swept over a smaller wavelength bandwidth is used for longer range imaging, and a VCL swept over a larger wavelength bandwidth is used for shorter range imaging.

16. The system of claim 13 wherein a VCL at a slower wavelength repetition frequency is used for longer range imaging, and a VCL at a faster wavelength repetition frequency is used for shorter range imaging.

17. The system of claim 1, wherein each of said N vertical cavity lasers is driven by a single tuning waveform having a first wavelength repetition frequency, each of said single tuning waveforms is a phase-translated copy of another of said single tuning waveforms, and said multiplexed wavelength-swept radiation has a second wavelength repetition frequency that is N times said first wavelength repetition frequency.

18. The system of claim 10, wherein at least one of said N vertical cavity lasers is driven at a mechanical resonance of a MEMS structure.

19. The system of claim 10, wherein at least one of said N vertical cavity lasers is driven in a vacuum environment.

20. The system of claim 10, wherein each of said N vertical cavity lasers is driven at a mechanical resonance of a MEMS structure.

21. The system of claim 10, further comprising a first MEMS-VCL having a first mechanical resonance frequency, and a second MEMS-VCL having a second mechanical resonance frequency substantially different from said first mechanical resonance frequency.

22. The system of claim 10, wherein each of said N vertical cavity lasers is in a vacuum environment.

23. The system of claim 19, wherein said vacuum environment is provided by an evacuated butterfly package.

24. The system of claim 19, wherein said vacuum environment is provided by an evacuated transistor outline package.

25. The system of claim 19, wherein a maximum driving voltage of said voltage source is less than 10V.

26. The system of claim 1, wherein said total wavelength range is contained within a range of about 750 nm-900 nm.

27. The system of claim 1, wherein said total wavelength range is contained within a range of about 950 nm-1150 nm.

28. They system of claim 1, wherein said total wavelength range is contained with a range of about 1200-1650 nm.

29. The system of claim 1, wherein said total wavelength range is contained within a range of about 1700-2300 nm.

30. The system of claim 1, wherein said sample is a human eye.

31. The system of claim 30, wherein said image includes a portion of an anterior eye and a portion of a retina of said human eye.

32. The system of claim 1, wherein said sample includes human tissue.

33. The system of claim 1, wherein said sample includes animal tissue.