| 摘要 |
PURPOSE:To excite a switching operation by means of a beam of low intensity by forming a reflectionless coating composed of a dielectric thin film on a beam-incident window installed on a saturable absorption region. CONSTITUTION:A distributed feedback type bistable semiconductor laser is composed of the following: an InGaAsP oscillation region 11; a p-electrode 2; p-InGaAsP 3; p-InP 5; p-InP 6; p-InP 7; an n-InP substrate 9; an n-electrode 10; a grating 11; a saturable absorption region; a light incidence window 13; a dielectric thin film 14; an output signal beam 18; input signal beams 15, 19. The secondary grating 11 is formed in the saturable region. Since a reflectionless coating composed of the dielectric thin film 14 is formed on the window 13 on which the input signal 15 is incident, the incidence efficiency of the input signal beam 15 is good; a switching operation is performed even by means of the input signal beam whose light intensity is weak. |
