Development of Compound-Semiconductor-Based Nonlinear Optical Devices Using Sublattice Reversal Epitaxy

点击翻译按钮获取中文摘要

1. Design and optimization of GaAs/AlGaAs nonlinear optical devicesWe have designed DFG devices for 1.55 μm band wavelength conversion bearing in mind the application to OXCs on future DWDM photonic network. AlGaAs QPM waveguids are expected to be polarization-independent and high-performance devices with conversion efficiencies as large as 700 %/W/cm^2. Estimated 3 dB bandwidth for 10-mm-long devices (30 % for 100 mW punp input) is 40 nm which covers the C band. On the other hand, GaAs QPM OPG/OPA/OPOs are expected to be usable in the finger-print wavelength region when fabricated with QPM periods of 〜 10 μm.2. Fabrication process of GaAs/AlGaAs QPM devicesWe have developed a device fabrication process for the AlGaAs/GaAs QPM wavelength conversion devices. The process consists of the GaAs/Ge/GaAs sablattice reversal epitaxy, flattening of the template by chemical etching or CMP, and regrowth techniques using MBE or MOVPE which maintain the vertical domain wall.3. Fabrication and characterization of AlGaAs QPM DFG devicesWe have fabricated 3rd-order QPM AlGaAs waveguiding DFG device for 1.55 μm band as a first prototype device. The flattening was achieved by the chemical etching. QPM SHG was achieved with a reasonable efficiency taking into account of the residual corrugation and the resulting propagation loss. Improved 1st order QPM devices with low propagation losses achieved by the CMP flattening process have been fabricated and the characterization of the wavelength conversion performance is now in progress.4. GaAs QPM optical parametric devicesGaAs QPM waveguiding parametric devices have been fabricated. A parametric fluorescence experiment using a Nd : YAG laser as a punp source is now underway.