All-optical data switching in an optical-fiber link using a GaAs optical bistable device

Abstract

We demonstrate the potential for all-optical processing of data transmitted over single-mode fibers using a bistable optical device (BOD). A stream of clock/bias pulses transmitted over a 1-km-long single-mode fiber (SMF) is processed by a pseudorandom data sequence of picosecond pulses transmitted over another 1-km SMF with the help of an optical bistable device. The processed signal from the BOD is transmitted over another kilometer of SMF and detected. The bistable device is an ~3-microm-thick molecular-beam epitaxially grown multiple-quantum-well structure of GaAs and GaAlAs. The clock pulses (at wavelength lambda = 870.0 nm) are just below the threshold for switching on the device, and the switching is accomplished by a pseudorandom data sequence of picosecond pulses (at lambda = 835.0 nm). The pulse width of the data transposed onto the clock stream by the BOD can be controlled by varying the phase of the switching data with respect to the clock, which may be of importance in interle aving data for time-division multiplexing. The experiment also demonstrates the potential of a BOD's capability of switching information from one wavelength to another. With optimized devices regeneration should be possible with reasonable gain.