Method and system for homogenizing diode laser pump arrays

Patent metadata

Field	Value
Publication number	US-9331452-B2
Application number	US-201313911787-A
Country	US
Kind code	B2
Filing date	Jun 6, 2013
Priority date	Aug 19, 2009
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

First claim

What is claimed is:

1. A method of fabricating a diffractive homogenizer, the method comprising:
providing a partially transmissive optical element having a predetermined grayscale intensity pattern thereon;
providing a transparent optical element; directing UV radiation through the partially transmissive optical element to impinge on the transparent optical element;
exposing a predetermined portion of the transparent optical element to the UV radiation; and
thermally treating the transparent optical element to produce the diffractive homogenizer characterized by a continuously varying index of refraction profile as a function of position within the transparent optical element.

2. The method of claim 1 wherein the continuously varying index of refraction profile is characterized by a dimension associated with diffraction effects for optical radiation.

3. The method of claim 1 wherein the transparent optical element comprises a piece of photo-thermo-refractive (PTR) glass.

4. The method of claim 1 further comprising exposing a second predetermined portion of the transparent optical element to the UV radiation.

5. The method of claim 4 wherein an area of the predetermined grayscale intensity pattern is smaller than an area of the predetermined portion of the transparent optical element and an area of the second predetermined portion of the transparent optical element.

6. The method of claim 1 wherein the partially transmissive optical element comprises a photographic image.

7. The method of claim 1 wherein the partially transmissive optical element comprises a spatial light modulator array.

8. The method of claim 1 wherein the transparent optical element comprises PTR glass.

9. The method of claim 8 wherein the PTR glass comprises a rectangular parallelepiped and the UV radiation impinges on the rectangular parallelepiped on a face normal to a smallest dimension of the rectangular parallelepiped.

Assignees

• Bayramian Andrew James
• L Livermore Nat Security Llc

Inventors

• Bayramian Andrew James

Classifications

• G02B27/0922

  the semiconductor light source comprising an array of light emitters · CPC title

• H01S5/405

  Two-dimensional arrays · CPC title

• G02B27/0927

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• H01S5/4012

  Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms · CPC title

• H01S3/094049 Primary

  Guiding of the pump light · CPC title