High-speed wavelength conversion in quantum dot and quantum well semiconductor optical amplifiers

We experimentally investigate wavelength conversion in quantum dot and quantum well optical amplifiers via four-wave mixing. Our results show superior conversion efficiency in a quantum dot device compared to a quantum well device with identical gain. Furthermore, a small-signal modulation bandwidth >25 GHz was measured with greater than 100% efficiency. Cross talk between two simultaneously input beams was found to be 20 dB below the signal power demonstrating the possibility for high-speed, multichannel performance. Cross-gain modulation measurements were performed as well and show a much smaller bandwidth of 1 GHz indicating that four-wave mixing is superior for high-speed signals. (C) 2008 American Institute of Physics.