INTERFEROMETER SEMICONDUCTOR LASER

PURPOSE: To enable change of frequency for emitted light by providing two electrodes, which can control the transmission and reflection of the laser light between segments at a beam splitter by current. CONSTITUTION: A semiconductor laser of an interferometer has three segments 1, 2 and 3 and a monitor diode 4. They are arranged at a right angle to each other on a rectangular semiconductor chip 10. The segments 1, 2 and 3, which are constituted as a plurality of the overlapped layers, and the monitor diode 4 are mutually connected with a beam splitter 5. Electrodes 51 and 52 are provided at the upper and lower parts of the beam splitter 5 at a height h0 at the region of four corners of the segments 1, 2 and 3 and the groove 18 of the monitor diode 4. The transmission and reflection of a holograph grid 121 are controlled, depending on the refractive index of the charge carrier concentration by current injection.