PURPOSE: To facilitate and simplify the manufacturing process of an element itself by integrating a material layer having optical conductivity modulation, introducing control light through the layer, and controlling a laser oscillation state.
CONSTITUTION: A suitable voltage is applied through an aluminum electrode 10 on a transparent electrode 9 to an optical conductivity modulation material layer 8 formed on a P-type cap layer 7 in a semiconductor laser. When light is incident externally in this state, the electric conductivity of the layer 8 is increased by an optical input P-in, and the voltage applied to a laser section (between P-type cap layer 7 and an N-type side electrode 1) is increased. When it exceeds a predetermined input power, it has a sufficient voltage value to generate a laser oscillation. Thus, even if the input power is thereafter increased, the optical output P-out is controlled for a laser oscillation with incident light externally without much variation. Thus, the manufacturing process can be simplified, and the diameter of the opening of the control incident light photodetecting area can be increased.
HISAMA KAZUO
HAMANAKA KOICHI
