INJECTION SYNCHRONOUS LASER OSCILLATOR AND OPTICAL COMMUNICATION SYSTEM USING THE OSCILLATOR

摘要

PROBLEM TO BE SOLVED: To provide an injection synchronous laser oscillator which can equalize the fundamental repetitive frequency of an injected light signal pulse train to a mode synchronous frequency and eliminates the need to use a circulator. SOLUTION: This laser oscillator has a semiconductor laser element which has a saturable absorption area 11 and a gain area 13 and also has an input surface where a light signal pulse train from an external light signal oscillation source is injected the end surface on the side of the saturable absorption area and an output surface on the end surface on the side of the gain area, a movable reflecting mirror (half-mirror) 15 which constitutes an external resonator with the end surface of the semiconductor laser element 1 on the saturable absorption area side, and a wavelength selecting element 17 which selectively sets the wavelength of a light clock pulse train synchronized with the light signal pulse train. In this case, a reflection preventive film 10 is formed on the end surface of the semiconductor laser element 1 on the side of the gain area 13.