LASER DIODE ASSEMBLIES

• US 20090245315A1
• Filed: 03/28/2008
• Published: 10/01/2009
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Victor Faybishenko
• Original Assignee: Victor Faybishenko
• Inventors: Faybishenko, Victor
• Granted Patent: US 7,733,932 B2
• Time in Patent Office: Days
• US Class Current: 372/50.120
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• 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 5/02251 using optical fibres
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/02326 Arrangements for relative positioning of laser diodes and optical components, e.g. grooves in the mount to fix optical fibres or lenses
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

Laser diodes (120) emit laser beams along a vertical YZ plane at different distances from the YZ plane. The beams are collimated in their fast and slow axes, and are redirected by turning mirrors (162) to form a beam stack (130C) traveling along the XZ plane. The beam stack is turned by about 90°, then converged by a focusing lens (174) into an optical fiber (180). A compact assembly is thus provided. Each laser diode (120.i), its collimating optics (154.i, 158.i, i=1, 2, . . . ) and its turning mirror (162.i) are rigidly attached to a flat, heat-spreading surface (144.i) and thus remain aligned with each other in thermal cycling.

Claims

1. An apparatus disposed in a region having a plurality of vertical sides comprising at least a first side, a second side, a third side, and a fourth side, wherein each of the second and fourth sides is between the first side and the third side, and each of the first and third sides is between the second side and the fourth side, the apparatus comprising:

(1) a plurality of laser diodes arranged to emit laser beams into the region in a direction or directions away from the first side, wherein the laser diodes'"'"' emitters are at different distances from at least one of the second and fourth sides; and

(2) optics for directing the laser beams to an output window, the optics comprising;

(2a) collimator optics for collimating the laser beams;

(2b) a first beam-redirector for directing the collimated beams to travel adjacent to the third side with the beams'"'"' slow axes overlying one another in a vertical cross section transverse to the beams;

(2c) a second beam-redirector for directing the beams received from the first beam-redirector to travel adjacent to the fourth side; and

(2d) focusing optics for converging the beams traveling from the second redirector to the output window.

2. The apparatus of claim 1 wherein the first side is at an angle of 71°

to 109°

to the second side, the second side is at an angle of 71°

to 109°

to the third side, the third side is at an angle of 71°

to 109°

to the fourth side, and the fourth side is at an angle of 71°

to 109°

to the first side.

3. The apparatus of claim 1 wherein the region is rectangular in top view, with a ratio of lengths of any two adjacent sides being at least 0.7 and at most 1.45.

4. The apparatus of claim 1 wherein the laser diodes and the optics are arranged to keep the beams separate from each other at least between the laser diodes and the first beam-redirector.

5. The apparatus of claim 1 wherein in a first cross section parallel to the first side and located at an entrance to the first beam-redirector, the beams'"'"' slow axes do not overlie one another or, if any slow axes overlie one another, an overlap between such slow axes is smaller than at an exit from the first beam-redirector in a second cross section orthogonal to the third side.

6. The apparatus of claim 1 comprising:

a plurality of laser diode structures, each laser diode structure comprising a discrete semiconductor structure comprising one or more of said laser diodes;

a plurality of generally flat, heat-dissipating surface regions for dissipating heat generated by the laser diodes, each laser diode structure being rigidly attached to a corresponding one of the flat, heat dissipating surface regions;

wherein each laser diode structure is associated with a portion of the collimating optics and the first beam-redirector for collimating and directing the beam or beams emitted by the laser diode structure, the portion being rigidly attached to the corresponding flat, heat-dissipating surface region, wherein the portions being spaced from each other.

7. The apparatus of claim 1 wherein the output window is an input of an optical fiber.

8. An apparatus comprising:

(1) a plurality of laser diodes arranged to emit laser beams whose optical axes do not overlie each other;

(2) optics for directing the laser beams to an output window, the optics comprising;

(2a) collimator optics for providing a plurality of collimated beams, each collimated beam being produced by collimating a corresponding beam emitted by the laser diodes;

(2b) a first beam-redirector for turning each collimated beam in a direction positioned in top view at an angle of 71°

to 109°

to the optical axis of the corresponding beam emitted by the laser diodes, and for positioning the beams'"'"' slow axes to overlie one another in a vertical cross section transverse to the beams;

(2c) a second beam-redirector for turning the beams received from the first beam-redirector, wherein in top view the beams entering the second beam-redirector form an angle or angles of 71°

to 109°

to the beams emerging from the second beam-redirector; and

(2d) focusing optics for converging the beams traveling from the second redirector to the output window.

9. The apparatus of claim 8 wherein in top view, for each said beam, the beam'"'"'s path to the first redirector, the beam'"'"'s path from the first redirector to the second redirector, and the beam'"'"'s path between the second redirector and the output window are arranged on third sides of a rectangle, and in the largest of said rectangles, a ratio of lengths of any two adjacent sides is at least 0.7 and at most 1.45.

10. The apparatus of claim 8 wherein the laser diodes and the optics are arranged to keep the beams separate from each other at least between the laser diodes and the first beam-redirector.

11. The apparatus of claim 8 wherein in a first vertical cross section transverse to the beams and located at an entrance to the first beam-redirector, the beams'"'"' slow axes do not overlie one another or, if any slow axes overlie one another, an overlap between such slow axes is smaller than in a second cross section orthogonal to the beams exiting the first beam-redirector.

12. The apparatus of claim 8 comprising:

a plurality of laser diode structures, each laser diode structure comprising a discrete semiconductor structure comprising one or more of said laser diodes;

a plurality of generally flat, heat-dissipating surface regions for dissipating heat generated by the laser diodes, each laser diode structure being rigidly attached to a corresponding one of the flat, heat dissipating surface regions;

wherein each laser diode structure is associated with a portion of the collimating optics and the first beam-redirector for collimating and directing the beam or beams emitted by the laser diode structure, the portion being rigidly attached to the corresponding flat, heat-dissipating surface region, wherein the portions being spaced from each other.

13. The apparatus of claim 8 wherein the output window is an input of an optical fiber.

14. An apparatus comprising:

a plurality of laser diode structures, each laser diode structure comprising a discrete semiconductor structure comprising one or more laser diodes;

a plurality of generally flat, heat-dissipating surface regions for dissipating heat generated by the laser diodes, each laser diode structure being rigidly attached to a corresponding one of the flat, heat-dissipating surface regions;

for each said laser diode structure, one or more collimators for collimating one or more laser beams emitted by the one or more diodes of the laser diode structure, and a turning mirror for turning the one or more collimated laser beams, the turning mirrors being for positioning the beams with their slow axes overlying each other, wherein for each laser diode structure, its one or more collimators and turning mirror are rigidly attached to the corresponding flat, heat-dissipating surface region.

15. The apparatus of claim 14 wherein at least two of the flat, heat-dissipating surfaces are parallel to each other and do not lie in a single plane.

16. The apparatus of claim 14 wherein at least two of the flat, heat-dissipating surfaces are not parallel to each other and do not lie in a single plane.

18. A method for manufacturing the apparatus of claim 14, the method comprising rigidly attaching the laser diode structures and the collimators to the flat, heat-dissipating surfaces.

17. A method for providing light to an output window, the method comprising:

generating laser light with a plurality of laser diodes, the laser light comprising a plurality of individual laser beams whose optical axes do not overlie one another;

collimating the individual laser beams;

redirecting the collimated individual laser beams to form a combined beam in which the individual laser beams'"'"' slow axes overlie one another, and directing the combined beam at an angle or angles of 71°

to 109°

with respect to the individual laser beams emerging from the laser diodes when viewed from the top;

turning the combined beam in a direction at an angle or angles of 71°

to 109°

when viewed from the top, thus directing the combined beam to pass through beam-converging optics to an output window.