Patent ID: 7515624

Claim:
A semiconductor laser reducing feedback-induced noise by a modulated optical output, comprising: an active layer having a light-amplifying region and a saturable absorber region formed to allow said semiconductor laser to be in a bistable state and to increase an amplitude of an optical output; a stochastic resonance electrode of a first polarity configured to inject a current generated by superimposing a noise current on a modulation current into said active layer and to control hysteresis by adjusting the intensity of said modulation current and the intensity of said noise current with respect to each other; and a stochastic resonance electrode of a second polarity provided in relation to said stochastic resonance electrode of the first polarity, wherein at least one of said stochastic resonance electrode of the first polarity and said stochastic resonance electrode of the second polarity is divided to allow said current to be injected independently into said light-amplifying region and said saturable absorber region, wherein said stochastic resonance electrodes control said hysteresis to adjust the lasing threshold of the laser and produce said optical output modulated as a stochastic resonance.