WAVEGUIDE TYPE OPTICAL DEVICE

摘要

There is provided a waveguide type optical device, the parasitic capacitance of which is reduced to enable the signal transmission speed to be increased. The waveguide type optical device has a bottom electrode (41) formed on a substrate (2), a bottom clad (51) formed on the bottom electrode (41), a bottom core (62) formed on the bottom clad (51), a top core (61) formed on the bottom core (62), a top clad (53) formed on the top core (61), and a top electrode (42) formed on the top clad (53). The top core (61) and the bottom core (62) are covered with a side clad layer (52) on both sides. The region where the top electrode (42) and the bottom electrode (41) are vertically overlapped with each other is located at the substantially same place as the core layer region including the top core (61) and the bottom core (62). The width of one of the top core (61) and the bottom core (62) is a width that satisfies a single mode condition, and the width of the other is substantially equal to the width of a field distribution or more.