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US 10,855,056 B2Granted
Power and brightness scaling in fiber coupled diode lasers using diodes with optimized beam dimensions
AssigneenLIGHT, Inc.
InventorsZhigang Chen, David Martin Hemenway, Manoj Kanskar
Life of this patent
Estimating the term…
Abstract
A number of beams that can be coupled into an optical fiber can be increased using emitted beams having greater divergence, thus providing increased beam power. Alternatively, with a fixed number of emitters, total optical power can be maintained with fewer beams in an output beam with a smaller numerical aperture.
Claims16
An apparatus, comprising:
- a set of laser diodes with a predetermined spacing with respect to a stacking axis, each laser diode having an emission region defining a fast axis and a slow axis that produces an emitted beam having a fast axis beam full width of less than 1.62 μm or a fast axis full width beam divergence of at least 48 degrees, wherein fast axes of each of the laser diodes are mutually parallel and are parallel to the stacking axis and slow axes of each of the laser diodes are mutually parallel and orthogonal to the stacking axis;
- fast axis collimators (FACs) associated with each of the laser diodes, each of the fast axis collimators having common focal length, wherein emission regions of each of the laser diodes are coupled to a respective fast axis collimator so as to produce respective beams that are collimated along the fast axes;
- a set of slow axis collimators (SACs) situated to receive respective beams from the FACs and produce beams that are collimated along the fast axes and the slow axes;
- an afocal telescope situated to receive the fast axis and slow axis collimated beams from the fast axis collimators and the slow axis collimators and produce a fast axis beam spacing based on the predetermined spacing and a magnification M associated with the afocal telescope;
- an objective lens situated to receive the fast axis and slow axis collimated beams from the afocal telescope, an optical fiber having a core situated to receive the fast axis and slow axis collimated beams from the objective lens, wherein the FACs and the objective lens have focal lengths fFAC and fO, respectively, a magnification of the emission regions of the laser diodes at the fiber is fO/MFA, and a fast axis numerical aperture of the fast axis collimated beams is NAFA=(dstair×m×M)/(2×fO), wherein m is a number of laser diodes in the set and dstair is the predetermined spacing, wherein fFAC is between 200 μm and 400 μm, fO is between 5 mm and 12 mm, and M is less than 0.9.
2 more elements
An optical beam source, comprising:
- a set of laser diodes situated to have a predetermined spacing along respective fast axes that are mutually parallel, each laser diode defined by a fast axis beam size less than 1.60 μm or a fast axis full width beam divergence of at least 48 degrees and having an emission region defining a fast axis and a slow axis, wherein fast axes of each of the laser diodes are mutually parallel and orthogonal to the stacking axis and slow axes of each of the laser diodes are mutually parallel and orthogonal to the stacking axis, wherein each of the diodes of the set of laser diodes emits in a wavelength range of 800 nm to 1,000 nm;
- fast axis collimators (FACs) and slow axis collimators (SACs) corresponding to each of the laser diodes of the set, each of the FACs have a common focal length fFAC and each of the SACs having a common focal length fSAC, wherein the FACs and SACs are situated to collimate optical beams emitted from respective emission regions of each of the laser diodes;
- an afocal telescope situated to receive the collimated beams and produce a fast axis beam spacing based on the predetermined spacing and a magnification M associated with the afocal telescope;
- and
- an objective lens situated to receive the beams from the afocal telescope and direct the beams to a focus, wherein the FACs and the objective lens have focal lengths fFAC and fO, respectively, a magnification of the emission regions of the laser diodes at the focus is fO/MfFA, and a fast axis numerical aperture of fast axis collimated beams is NAFA(dstair×m×M)/(2×fO), wherein m is a number of laser diodes in the set and dstair is the predetermined spacing.
2 more elements
An apparatus, comprising:
- a set of laser diodes with a predetermined spacing with respect to a stacking axis, each laser diode having an emission region defining a fast axis and a slow axis that produces an emitted beam having a fast axis beam full width of less than 1.62 μm or a fast axis full width beam divergence of at least 48 degrees, wherein fast axes of each of the laser diodes are mutually parallel and are parallel to the stacking axis and slow axes of each of the laser diodes are mutually parallel and orthogonal to the stacking axis, wherein the laser diodes are flared laser diodes;
- fast axis collimators (FACs) associated with each of the laser diodes, each of the fast axis collimators having common focal length, wherein emission regions of each of the laser diodes are coupled to a respective fast axis collimator so as to produce respective beams that are collimated along the fast axes;
- a set of slow axis collimators (SACs) situated to receive respective beams from the FACs and produce beams that are collimated along the fast axes and the slow axes;
- an afocal telescope situated to receive the fast axis and slow axis collimated beams from the fast axis collimators and the slow axis collimators and produce a fast axis beam spacing based on the predetermined spacing and a magnification M associated with the afocal telescope;
- an objective lens situated to receive the fast axis and slow axis collimated beams from the afocal telescope, an optical fiber having a core situated to receive the fast axis and slow axis collimated beams from the objective lens, wherein the FACs and the objective lens have focal lengths fFAC and fO, respectively, a magnification of the emission regions of the laser diodes at the fiber is fO/MfFA, and a fast axis numerical aperture of the fast axis collimated beams is NAFA=(dstair×m×M)/(2×fO), wherein m is a number of laser diodes in the set and dstair is the predetermined spacing.
2 more elements
Dependencies are inferred from the claim text.