Resonant Tunneling Quantum Well Integrated Optical Waveguide MOdulator/Switch

摘要

In this Phase I program, Physical Optics Corporation (POC) has investigatedresonant tunneling double barrier quantum wells (RTDBQW) for application to all-optical communication networks. The RTDBQW can be used as a building block in superfast SONET/ATM network. The proposed concept relies on the integration of an optical guided wave modulator with the RTDBQW. Several waveguide modulator architectures have been investigated, including Mach-Zehnder directional couplers. A Mach-Zehnder interferometer has been selected for the final implementation and will provide high performance. The major advantage of the proposed integrated optical waveguide modulators/switch is that it uses low voltage due to the use of the high efficiency RTDBQW diode. This, in turn, increases the theoretical speed limit of the device to the femtosecond regime. One important feature of the RTDBQW device is that its response time is limited by quantum tunneling time, not by the conventional diode transit time, which leads to high speed operation.