SPECTRAL LINEWIDTH CONTROL DEVICE FOR SEMICONDUCTOR LASER BEAM SOURCE

摘要

PROBLEM TO BE SOLVED: To provide a low-cost spectral linewidth control device, facilitating optical system composition, without increasing adjusting steps, within an outer resonator type semiconductor laser beam source. ;SOLUTION: An outer resonator type laser beam source is composed of a semiconductor laser oscillator by a semiconductor laser 11 having a non- reflecting mirror 12, a reflecting mirror 6 comprising a resonator together with the oscillator, and a laser drive circuit 14. Furthermore, the laser beam source is provided with a random noise producer 3, convoluting an output current with a laser driving current, a switch 15 convoluting and disconnecting the noise current with and from the laser drive current, as well as a controller 16 controlling the switch transfer operation and the noise current of the random noise current of the random noise producer 3. Through these procedures, the noise current by the random noise producer 3 is convoluted with the laser driving current at an arbitrary amplitude through the intermediary of the switch 15 by the controller 16. In such a constitution, the fluctuation in the laser drive current by the noise current becomes the fluctuation in optical frequency, thereby equivalently widening the spectral linewidth.;COPYRIGHT: (C)1998,JPO