Hybrid integration of GaInAsP laser diode on silicon platform by epitaxial growth using direct bonded InP/Si substrate is presented. InP/Si substrate was prepared by hydrophilic direct bonding with 1μm thickness of InP layer and silicon substrate annealed at 400°C. GaInAsP/InP double heterostructure was grown by low pressure MOVPE system on the InP/Si substrate. Lasing characteristics were obtained at room temperature by injecting the current through the bonding interface between InP and Si. The threshold current density was comparable to the same laser structure grown on the InP substrate.
We have proposed the optical deflector using arrayed waveguides that have different refractive index fabricated by MOVPE selective area growth. By placing the asymmetric width of SiO<sub>2</sub> mask pattern on both sides of the arrayed waveguide, the thickness of each waveguide in the array has changed gradually. And the phase change in each arrayed waveguide results the deflection of the light. In this device, we have numerically calculated and fabricated the 1xN multi-mode interference (MMI) star coupler using GaInAs/InP MQW structure to input the light equally for each arrayed waveguide. From the numerical calculation, we obtain 0.42dB fluctuation of the output light power in each waveguide in the 1x16 MMI waveguide. In the experiment, we fabricated the 1x16 MMI waveguide using GaInAs/InP MQW structure, and 0.88dB fluctuation of the output light was obtained for the 1.56μm wavelength input light.
And further, we have numerically calculated the wavelength demultiplexing and switching performance in this device. We have obtained the wavelength dependence of output power in 8 arrayed waveguides that have 1.0% refractive index difference in both sides of the arrayed waveguide. From this analysis, we can exchange the output ports of each wavelength by controlling the refractive index in the arrayed waveguide.
New type optical deflector with graded refractive index region has proposed. For this device, two types structure that are multi electrode type and comb like electrode type have been numerical analyzed using Finite Difference Beam Propagation Method, and have shown the structural dependence on the deflection angle and the deflection efficiency, etc. We fabricated this optical deflector using GaInAs/InP MQW structure, and we confirmed the fundamental optical deflector using GaInAs/InP MQW structure, and we confirmed the fundamental optical deflection and the wavelength dependence of the device.
The gate length dependencies of the optical response characteristics in the optically controlled MOSFET have measured. This device was the integrated structure of absorption region and MOSFET region by using direct wafer bonding technique. By reducing the gate length of MOSFET region, the transconductance of FET channel was increased, and we obtained high current modulation and responsivity by irradiation of 1.5 micrometer wavelength light.