Vertically Coupled GaAs Microdisk Resonators by Low Temperature Adhesive Wafer Bonding

　　In this thesis, we bonded a GaAs sample with SiNx waveguides onto a Si substrate by a low temperature adhesive wafer bonding method with benzocyclobutene. Then, we removed the GaAs substrate using citric acid to selectively etch GaAs against the AlGaAs layer. Thus, we successfully fabricated GaAs microdisks vertically coupled with SiNx waveguides. 　　We investigated the coupling behavior due to different lateral positions between waveguides and microdisks of 50μm in diameter. The free spectral range is about 3nm, which is rather small and results in a complicated modal structure. 　　Therefore, we fabricated microdisks of 20μm in diameter and discuss its coupling behavior when the lateral position between the microdisk and the waveguide is changed. The free spectral range is increased to 9.41nm. The lateral position with highest quality factor of 17800 is achieved when the microdisk overlaps with the waveguide by 3.7μm.