Design, fabrication, and characterization of a two-dimensionalphotonic-crystal symmetric Mach-Zehnder interferometer for opticalintegrated circuits

• Published in: Applied physics letters 2005-03, Vol.86 (14), p.141104-141104-3
• Main Authors: Tanaka, Yu, Sugimoto, Yoshimasa, Ikeda, Naoki, Nakamura, Hitoshi, Kanamoto, Kyozo, Asakawa, Kiyoshi, Inoue, Kuon
• Format: Article
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1898431

We report on the design, fabrication, and optical characterization of a GaAs two-dimensional photonic-crystal-based symmetric Mach-Zehnder interferometer (PC-SMZ) aimed at all-optical switches in planar photonic integrated systems. The directional couplers that constitute the PC-SMZ interferometer prevent the occurrence of ring resonance which degrades the interference, and allow control pulses for the switching operation to be received. We show 50%- and 100%-power couplings from the transmission characteristics of the directional couplers, thus demonstrating their operation as 3-dB dividers in the PC-SMZ. We also show experimentally wavelength selectivity between signal and control pulses with a separation of ∼ 7 nm . These results indicate that the structure is promising as an all-optical switch when a nonlinear material such as a quantum dot is introduced into both arms of the interferometer.