Abstract

As bit rates per channel increase in modern optical communication systems, simple and stable optical pulse sources are needed because the RZ format is preferred at high bit rates.¹ Gain-switched lasers and mode-locked lasers have been frequently used as optical pulse sources. However, the former is subject to large frequency chirping and timing jitter while the later are more difficult to maintain and have problems in controlling the repetition cycles of the pulses. Electro-absorption (EA) modulators have been used to generate optical pulses with sinusoidal RF drive² and overcome these difficulties. The advantages of EA modulators include low-chirp, low jitter, and high-speed. However, high bias voltages and hence high driving powers are usually required to generate shorter pulses. Traveling-wave EA modulators (TWEAM) have been previously demonstrated in low driving power operation without sacrificing bandwidth.³ In this work, we fabricated a multi-quantum-well (MQW) TWEAM to further improve the modulation efficiency and used it to generate optical pulses at 40 GHz repetition rate.

© 2002 Optical Society of America