Abstract

We report the first realization of an AlGaAs/GaAs broadband integrable optical correlator with the potential of subpicosecond pulse measurement. The correlation action is based on the surface emitting second harmonic generation technique developed earlier.^1,2 Following the technique described in Ref. ², as the fundamental pulsed beam propagates in a waveguide cavity, the forward and backward propagating TE₀ and TM₀ beams interact via the nonlinearity of the waveguide material (in our case GaAs) to generate a standing wave of second harmonic polarization along the length of the waveguide cavity. The period of the standing wave polarization is proportional to the difference in the propagation constant of TE₀ and TM₀, and the envelope of the second harmonic signal is proportional to the pulse width of the fundamental beam; 7-ps compressed pulses at 1.06 μm were coupled to an AlGaAs/GaAs waveguide cavity. The average (peak) power in the cavity is estimated in be 100 μm (140 mW). A 1600 Fuji film was used to record the envelope of the green light (0.532 μm) across the waveguide. Using a sinclike function for the pulse shape, a pulse width of 7 ps is determined.

© 1988 Optical Society of America