Method and system for homogenizing diode laser pump arrays
View Patent ↗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%.
1. An optical amplifier system comprising:
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 being measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars, wherein 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%;
a diffractive optic disposed along the optical path, wherein the diffractive optic comprises a photo-thermo-refractive glass member; and
an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance, wherein 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%.
2. The optical amplifier system of claim 1 wherein the photo-thermo-refractive glass member comprises a continuous variation in the index of refraction.
3. The optical amplifier system of claim 1 wherein the photo-thermo-refractive glass member is substantially free of sinusoidal grating structures.
4. The optical amplifier system of claim 1 wherein the diffractive optic includes grating structures having a pattern that is defined based on an intensity profile present at an input face of the diffractive optic and a desired intensity profile at the amplifier slab.
5. The optical amplifier system of claim 1 further comprising one or more lenses disposed along the optical path between the diffractive optic and the amplifier slab.
6. The optical amplifier system of claim 1 wherein the photo-thermo-refractive glass member has a first planar surface opposing a second planar surface.
7. The optical amplifier system of claim 1 wherein the first intensity profile has a variation between 10% and 300%.
8. The optical amplifier system of claim 7 wherein the first intensity profile has a variation between 10% and 100%.
9. The optical amplifier system of claim 8 wherein the first intensity profile has a variation between 10% and 50%.
10. The optical amplifier system of claim 1 wherein the second intensity profile has a variation between 1% and 10%.
11. The optical amplifier system of claim 10 wherein the second intensity profile has a variation between 2% and 5%.
12. The optical amplifier system of claim 1 wherein the diffractive optic comprises grating structures having a pattern that is neither periodic nor chirped.