Semiconductor laser modulator

Abstract

Abstract PURPOSE:To modulate the output of a semiconductor laser regardless of temperature as desired by providing a modulation signal input terminal at a controller to generate a control signal to provide predetermined relationship between the modulation signal and a photo receptor. CONSTITUTION:A photo receptor 4 receives part 3 of the output light from a semiconductor laser 2 to convert in into an electric signal and to apply it to a controller 5. The controller 5 so generates a control signal as to provide predetermined relationship between the standard voltage and the output of the photo receptor 4. A drive unit 6 supplies current to the laser 2 in accordance with the control signal from the controller 5. When the modulation signal is applied as a standard voltage from a modulation input terminal 7, the output light intensity from the laser 2 can be varied by the modulation signal. Since the temperature characteristics of the photo receptor 4 and the controller 4 can be lowered sufficiently, the modulating function of the modulator 1 does not almost affect according to the temperature. Thus, the modulator can modulate the frequency determined by the time constant of the modulator 1 from the direct current regardless of the temperature change of the semiconductor laser.

Inventors

• 👤 Toyohiro Takimoto
• 👤 Kenji Horikiri
• 👤 Kenji Ikeda

Bibliographic Details