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Miniaturization of optical logic devices has long been considered to be a key to minimizing their energy requirements but was also considered difficult to achievel-4 .. We demonstrate a straightforward technique for fabricating arrays of GaAs,'"Fabry-Perot etalon devices (microrronators) as small as 1.5 μm in diameter. The growth of integrated GaAs-AlAs nonlinear etalons by molecular beam epitaxy (MBE) offers much improved manufacturability and uniformity over previous fabrication techniques From From the sample of reference' 5 we have formed close-packed arrays of monolithic "posts" or microresonators 1.5- 5 μm across by ion-beam assisted etching and have performed optical NOR/OR gating experiments on them using picosecond. pump and probe pulses. These microresonators represent a qualitative advance over the GaAs devices reported by Lee et al .8. In that work peels 9x 9 μm square were formed in the active material only, and then sandwiched between dielectric mirrors in the usual way Growth of integrated devices by 'epitaxial. techniques such as MBE allows us to etch right through both mirrors and the active material. This is critical since in an optimized nonlinear etalon the dielectric mirrors comprise most of the total thickness. The lateral optical confi.nement in these waveguidiv ttructures allows efficient operation with diameters as small as one can focus the light. Elimination of carrier diffusion. "1 out of the devices permits very close spacig. Reduction of energy requirements is expected d e to the decreased volume of interaction. Finally, surface recombination ".' on the aidewalla of the microresonators should produce fast relaxation times. Our experiments show more than an order of magnitude reducion in energy requirements, essentially uniform response over small arrays, practically no crosstalk with 3-μm center-center ,spacing, 150 ps full recovery time, and thermal stability at 82 Mllz operating frequency.
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