Multibeam coherent laser diode source (embodiments)

• US 8,401,046 B2
• Filed: 07/07/2010
• Issued: 03/19/2013
• Est. Priority Date: 07/17/2009
• Status: Expired due to Fees

• Current Assignee: General Nano Optics Limited
• Original Assignee: General Nano Optics Limited
• Inventors: Shveykin, Vasiliy Ivanovich, Gelovani, Viktor Archilovich, Sonk, Aleksey Nikolaevich
• Primary Examiner(s): Zhang, Yuanda
• Assistant Examiner(s): NGUYEN, TUAN N
• Application Number:
  US13/384,531
• Publication Number:
  US 20120113998A1
• Time in Patent Office: 986 Days
• Field of Search: 372/69, 372/75, 372/45.01
• US Class Current: 372/31
• CPC Class Codes: H01S 5/026 Monolithically integrated components, e.g. waveguides, monitoring photo-detectors, drivers stabilisation of output H01S5/06
• CPC Class Codes: H01S 5/0265 Intensity modulators intra-cavity modulators H01S5/0625
• CPC Class Codes: H01S 5/1007 Branched waveguides
• CPC Class Codes: H01S 5/1064 varying width along the optical axis
• CPC Class Codes: H01S 5/1085 Oblique facets
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/2214 based on oxides or nitrides
• CPC Class Codes: H01S 5/4006 Injection locking
• CPC Class Codes: H01S 5/42 Arrays of surface emitting lasers

Abstract

A multibeam coherent laser diode source comprises a master laser, a linear amplifier and two perpendicular amplifiers. The master laser and amplifiers are in the form of a single heterostructure containing an active layer, two limiting layers and a radiation influx area with an influx layer. The heterostructure is characterized by the ratio of the refractive index of the heterostructure to the refractive index of influx layer. This ratio is determined from a range extending from one plus delta to one minus gamma, where delta and gamma are defined by a number much less than one and gamma is greater than delta. The linear amplifier is positioned so that optical axis of radiation propagation from master laser coincides with the axis of the linear amplifier. Each perpendicular amplifier has output edge and is positioned so that its optical axis is situated at right angle to the axis of linear amplifier.

Claims

1. A diode source of multibeam coherent laser emission containing

at least one master laser, the master laser being a single-mode single-frequency master diode laser,

at least one linear amplifier, the linear amplifier being a diode optical amplifier integrally and optically connected with said master laser,

at least two perpendicular amplifiers, the perpendicular amplifiers being diode optical amplifiers integrally and optically connected with the linear amplifier;

said master laser, said linear amplifier and said perpendicular amplifiers being formed in a common heterostructure based on semiconductor compounds, said heterostructure containing

at least one active layer,

at least two cladding layers, and

an emission leak-in region transparent for emission, said leak-in region being placed between the active layer and a corresponding cladding layer at least on one side of the active layer and containing at least a leak-in layer, wherein said heterostructure is characterized by the ratio of the effective refractive index n_eff of the heterostructure to the refractive index n_IN of the leak-in layer, namely, the ratio of n_eff to n_IN being in the range from one to one minus gamma, where gamma is determined by a number much less than one;

said master laser including

an active stripe lasing region with connected metallization layers,

a lateral emission confinement region with a connected insulating layer, said confinement region being located on each lateral side of the active stripe lasing region of the master laser,

ohmic contacts,

optical facets,

reflectors, and

an optical resonator, and wherein on both optical facets the reflectors of the optical resonator have reflection coefficients near one and are placed in the specified vicinity of location of the active layer of the heterostructure;

the linear amplifier including at least an active amplification region with connected metallization layers located such that an optical axis of propagation of emission of the master laser coincides with an optical axis of the linear amplifier;

the perpendicular amplifier including at least an active amplification region with connected metallization layers and an optical output facet with an optical antireflection coating being located such that the optical axis of the perpendicular amplifier is located at a right angle (modulus) to the optical axis of the linear amplifier;

and wherein in a vicinity of an intersection of the optical axis of the linear amplifier with the optical axis of each perpendicular amplifier there is a rotary element for flow of a specified portion of laser emission from the linear amplifier to the perpendicular amplifier, said rotary element including at least one optical reflecting plane perpendicular to the plane of the layers of the heterostructure, crossing the active layer and part of the leak-in region within a thickness of the leak-in layer from 20% to 80%, and making angles of inclination with the optical axes of the linear amplifier and of the perpendicular amplifier of about 45°

(modulus).

2. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the reflectors of the optical resonator of the master laser are located on each optical facet from a surface of the heterostructure to a specified depth in the leak-in region.

3. The diode source of multibeam coherent laser emission as defined in claim 1 wherein on each side of the optical resonator of the master laser there is one linear amplifier.

4. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the reflectors of the optical resonator of the master laser are distributed Bragg reflectors.

5. The diode source of multibeam coherent laser emission as defined in claim 1 wherein in the lateral confinement region of the master laser there is at least one dividing-confinement subregion and at least one confinement subregion, the dividing-confinement subregion of a specified width is located on both lateral sides of the active lasing region of the master laser from a surface of the heterostructure to a specified depth, not reaching the depth of location of the active layer, the confinement subregion is located on both lateral sides of said dividing-confinement subregion from the surface of the heterostructure to a specified depth exceeding the depth of location of the active layer.

6. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the active amplification region of the linear amplifier is widening at least at part of its length on the side of the master laser.

7. The diode source of multibeam coherent laser emission as defined in claim 6 wherein there is a smooth transition of said widening part to the stripe part.

8. The diode source of multibeam coherent laser emission as defined in claim 1 wherein each lateral side of the active amplification region of the linear amplifier has a dividing-confinement subregion of a specified width placed from a surface of the heterostructure to a specified depth, not reaching the depth of location of the active layer.

9. The diode source of multibeam coherent laser emission as defined in claim 8 wherein each lateral side of the dividing-confinement subregion has a confinement subregion placed from the surface of the heterostructure to a depth exceeding the depth of location of the active layer.

10. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the active amplification region of the perpendicular amplifier is widening at least at certain part of its length on the side of the linear amplifier.

11. The diode source of multibeam coherent laser emission as defined in claim 10 wherein there is a smooth transition of said widening part to the stripe part.

12. The diode source of multibeam coherent laser emission as defined in claim 1 wherein each lateral side of the active amplification region of the perpendicular amplifier has a dividing-confinement subregion of a specified width placed from a surface of the heterostructure to a specified depth, not reaching the depth of location of the active layer.

13. The diode source of multibeam coherent laser emission as defined in claim 12 wherein each lateral side of the dividing-confinement subregion has a confinement subregion placed from the surface of the heterostructure to a specified depth exceeding the depth of location of the active layer.

14. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the optical reflecting plane of a rotary element maximally removed from the reflector of the optical resonator of the master laser is located from a surface of the heterostructure to the cladding layer on the side of the substrate.

15. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the optical antireflection coating on the optical facets of output of amplified emission of the perpendicular amplifier has a reflection coefficient near zero.

16. The diode source of multibeam coherent laser emission as defined in claim 1 wherein the optical reflecting plane of the rotary element has an angle of inclination of plus 45°

, the optical reflecting plane of the rotary element next to said optical reflecting plane has an angle of inclination of minus 45°

.

17. The diode source of multibeam coherent laser emission as defined in claim 1 wherein in the common heterostructure there are at least two active layers electrically connected to one another by thin heavily doped layers of the p-type and the n-type with a tunnel transition between them.

18. The diode source of multibeam coherent laser emission as defined in claim 1 wherein at least each master laser, each linear amplifier, and each perpendicular amplifier have independent ohmic contacts.

19. The diode source of multibeam coherent laser emission as defined in claim 1 wherein along the active amplification region of at least one of the perpendicular amplifiers in the direction of an optical axis of propagation of a twice amplified laser emission at a certain distance from the rotary element there is at least one introduced output element including at least one optical reflecting plane crossing the planes of a number of heterostructure layers at an angle of inclination of 45°

(modulus) including the active layer and partially the leak-in layer, namely, from 30% to 80% of its thickness.

20. The diode source of multibeam coherent laser emission as defined in claim 19 wherein the optical reflecting plane of an output element maximally removed from the rotary element is from a surface of the heterostructure to the cladding layer on the side of the substrate.