A BEAM-SHAPING AMPLIFIER CONTAINING A CRYSTALLINE GAIN MEDIUM

摘要

A laser beam-shaping amplifier (100) has a doped crystalline gain medium (102) having a longitudinal axis and a radially-varying doping profile (404; 04). The amplifier (100) also has a coupler (104) for coupling a laser beam (110) outputted from a laser (108) to the gain medium (102) and an excitation source (106; 206) operable to excite the gain medium (102). In use, a laser beam (110) having an input beam profile (402; 502) generated by the laser (108) is out-coupled to the gain medium (102) and amplified in accordance with the radially-varying doping profile (404; 504), thereby changing the beam profile to produce an output laser beam (112) having an output beam profile (406; 506) which is different from the input beam profile (402; 502).