Stabilizing system of optical output

Abstract

Abstract PURPOSE:To keep a peak value constant while maintaining a desired extinction ratio by independently controlling bias currents and the level of a pulse signal when the pulse signal is overlapped to DC bias currents and a semiconductor laser is driven by using a drive signal obtained by the overlapped currents. CONSTITUTION:A PCM input signal from a gate circuit G is converted into a level, which can be driven, by a driver DRIV, an output from the driver and bias currents from a comparator COM2 are overlapped by an adder ADD, and the semiconductor laser LD is driven by a signal from the adder. The backward output of laser beams from a laser LD is received by using an avalanche photodiode APD, an output from the photodiode is amplified by a wide zone amplifier AMP, and added to a peak detector DET2, and the peak value is clamped first, and DCs are cut by a DET3, and pulse height is detected. The difference is compared with reference voltage by the comparator COM2, pulse height is compared by a COM1, and bias currents and the pulse signal are controlled separately.

Inventors

• 👤 Masaru Onishi
• 👤 賢 大西
• 👤 Nobuhide Yamaguchi
• 👤 山口　伸英
• 👤 Kimiyoshi Okada
• 👤 岡田　公芳

Bibliographic Details