Semiconductor laser device

Abstract

Abstract PURPOSE:To compensate for distortion generated in analog modulation, by converting an input modulation signal to a frequency generating the distortion with a frequency multiplier, shifting the phase by 180 deg. with a phase shifter, attenuating the amplitude with an attenuator, and again combining it with the original signal. CONSTITUTION:Input modulation signal 1 is branched into an original signal and a signal for distortion compensation; the branched signal for distortion compensation is converted to a frequency generating the distortion with a frequency multiplier 2; the phase is shifted by 180 deg. with a phase shifter 3; the signal level is adjusted to be a desired value with a variable attenuator 4; the obtained signal is again combined with the original signal, and inputted, as a modulation signal, in a laser 6. Hence the generated optical higher harmonic signal is canceled by the signal whose phase is shifted by 180 deg., and only the input modulation signal component can be led out. Thereby analog transmission free from distortion is realized.

Inventors

• 👤 Hitoshi Watanabe
• 👤 渡辺　斉

Bibliographic Details