SEMICONDUCTOR LASER

PURPOSE:To eliminate a light reflecting surface for forming an optical resonator by providing first and second optical guides connected with a light emitting unit, and a feedback guide having first and second optical transfer units. CONSTITUTION:An optical looplike feedback guide 23 connected with first and second photodetecting diodes 4, 4a has first and second optical transfer units 23a, 23b which approach to first and second guides 21, 22 of lengths L1 and L2 in parallel with the guides 21, 22 for communicating lights to be propagated. The propagating length of the light propagated between first and second optical transfer units 23a and 23b to be fed back to a light emitting unit 3 is integer times as large as the wavelength of a laser light to generate an optical resonance in an active layer. Since a quantum amplification is performed due to inductive emission in the unit 3 by such guides 23, the light reflecting surface for forming an optical resonator can be eliminated.