Surface Micromachining in Optical Isolator with Semiconductor Guiding Layer for Enhancement of Magnetooptic Effect

A magnetooptic waveguide with a magnetic garnet/GaInAsP/air structure was effective in enhancing the magnetooptic effect. Surface micromachining was investigated for fabricating a magnetooptic waveguide in an optical isolator with a semiconductor guiding layer. As a preliminary experiment, a GaInAsP rib waveguide with an air cladding layer was fabricated by selective wet etching. The rib waveguide with a 1-mm-long air bridge was successfully obtained on the GaInAsP guiding layer. Light waves could be guided in the GaInAsP waveguide with the air bridge structure.