Patent ID: 7764723

Claim:
A high brightness pump module outputting a pump light at a pump wavelength which is coupled into a fiber gain block generating an output light at a lasing wavelength different from the pump wavelength, the pump module comprising: a plurality of laser diodes individually coupled to a bottom of a housing in a stepwise manner and generating respective pump lights which propagate along respective parallel light paths; a plurality of groups of optical components coupled to the bottom of the housing, each group having first and second collimating components and a bending mirror, wherein the optical components of each group are aligned with the laser diode; an objective lens located in the housing downstream from the groups and configured to receive the pump lights from the bending mirrors and couple the received pump lights into an output optical fiber which guides the pump lights towards the gain block; a plurality of dielectric layers each having a first sub-layer of material with a high index of refraction and a second sub-layer of material with a low index of refraction, the dielectric layer being coated on an element selected from the group consisting of at least one of the optical components of the group, objective lens and output fiber and a combination thereof to prevent backreflected light at the lasing wavelength from propagating towards the laser diode.