LASER TUNING BY OPTICAL PATH LENGTH VARIATION USING LIQUID CRYSTAL

摘要

PROBLEM TO BE SOLVED: To provide an improved device for laser tuning. SOLUTION: A device for laser tuning comprises an external cavity (2) for receiving a laser beam (4). The laser beam (4) travels in a material along a path (4) between a cavity end part element (6) and a tuning element (8), and the path (4) has an optical path length. A spectroscopic element (10) is inserted in the path (4) of the laser in order to select at least one mode of the laser, and a changing element is disposed to change the optical path length of the path (4). The changing element is formed of liquid crystals (32 and 42) having sensitive properties. The respective properties of the liquid crystals (32 and 42) are so changed as to influence the optical path length of the path (4) and stabilize the mode of the laser.