Control of photonic crystal structure for practical application

- Realization of ultrasmall and ultrafast all-optical switch -

Abstract

Techniques of controlling a two-dimensional photonic crystal (2DPC) structure are reviewed, focusing on the precise nanofabrication of air-hole lattices and functional waveguide design in light of application to an ultrasmall and ultrafast symmetric Mach-Zehnder-type all-optical switch (PC-SMZ). In a typical GaAs-based air-bridge- type 2DPC structure, transmission spectra in good agreement with the calculated result　and low propagation loss of less than 1 dB/mm are reproducibly exhibited, while directional couplers with arbitrary and wavelength-dependent coupling strengths play important roles as practical beam splitters/couplers. Through the recent switching operation of the PC-SMZ, the possibility of far advancement of 2DPC-based integrated circuits is concluded.