Abstract

We have demonstrated an integrated- optical serial-to-parallel converter based on surface-emitting second harmonic generation. The SHG is produced when two counter-propagating waves overlap inside a nonlinear 1 -μm-thick multilayer Al_0.9Ga_0.1 As/Al_0.7Ga_0.3As waveguide. As a proof of concept, we input two 2-ps 1,32-μm pulses into the waveguide. Counter-propagation is achieved by Fresnel reflecting the input pulses at the waveguide–air interface or by coating one end of the waveguide to form a mirror. As expected, by controlling the pulse separation, we were able to control precisely where the pulses collide inside the waveguide and hence predict the positions at which the SHG will be emitted. The device can handle pulses spaced as close as 4 ps (0.2 mm in the waveguide), corresponding to a 250 Gb/s data rate. By placing a detector over each collision site, serial-to- parallel conversion can be accomplished. In addition, this device can also be used as a demultiplexor and for code-recognition in a code-division multiplexing scheme.

© 1992 Optical Society of America