Field-driven all-optical wavelength converter using novel InGaAsP/InAlGaAs quantum wells.

A new type of semiconductor quantum well (QW) for high-speed all optical wavelength converter (AOWC) is proposed and demonstrated in this work. Based on InGaAsP (well)/InGaAlAs (barrier) multiple QW, large electron band offset ratio relative to heavy hole can be attained to shorten sweep rate of photocarrier driven by electric field, realizing high-speed efficient AOWC through cross absorption modulation (XAM). By such QWs, an optical waveguide with high-speed electrode connection is fabricated. A -3dB bandwidth of 38 GHz with 8V bias in time-varying photocurrent and all optical response is observed. The corresponding sweep time is less than 10ps, consistent with calculated tunneling rate of QW and thus confirming high sweep rate through field-driven tunneling processing. All-optical conversion with error-free 40Gb/s data transmission and -11dB of conversion efficiency in system performance is also attained in this device, suggesting that such AOWC has potential for 100Gb/s application.