LASER WITH SWITCHABLE POLARIZATION

摘要

2058931 9100631 PCTABS00003 A laser device includes a resonant cavity with a gain medium (10) therein, and first (14a) and second reflectors (14b) at either end, to form a quasi-isotropic laser. A feedback section is formed between the second reflector and a third reflector (22). A polarizer (24) and modifier (26) are provided in the feedback section. The polarizer and modifier can modify a variety of parameters, for example the polarization, phase, intensity or frequency of the feedback. The light feedback into the resonant cavity has an intensity much less than that within the resonant cavity, but sufficient to overcome any residual anisotropies. Control of the modifier causes the device to be operated in one of two or more polarization modes.