STABILIZATION OF OSCILLATION FREQUENCY OF SEMICONDUCTOR LASER AND DEVICE THEREFOR

摘要

PURPOSE:To contrive to stabilize the oscillation frequency of a semiconductor laser on one side by a method wherein an optical beam from a second semiconductor laser having a frequency different from that of the semiconductor laser on one side are received simultaneously and a beat signal which is generated by the interference of the light is fed back to the control circuit of the semiconductor laser on one side. CONSTITUTION:Light reflected by a beam splitter 7 is transmitted a linear polarizer 8 and a condensing lens 9, which are arranged at such a proper magnetic declination that two-component lights generate an interference, is incided in a photoelectric conversion means 10 and is converted into an electrical signal proportioned to its optical intensity. The electrical signal converted by the means 10 is a signal having a frequency equal to a difference between the frequencies of the two-component lights. This frequency signal is converted into a voltage by an F/V converter 11. This voltage is compared with a value set in advance by a comparator 15 and the injected current to an LD1 is changed by a current control circuit for the LD1 on the basis of the result. Thereby, the oscillation frequencies of the LD1 and an LD2 can be stabilized at the setpoint.