| 摘要 |
PROBLEM TO BE SOLVED: To improve wavelength control efficiency for resonance wavelength without degrading modulation efficiency in a case of using a doped silicon layer or a silicide layer as a heater.SOLUTION: A ring optical modulator includes: a ring waveguide 1 including a ring waveguide core 1A that is a rib section of a silicon layer and including a p-doped area and an n-doped area; a bus waveguide 2; an inner circumference electrode line 3 provided along an inner circumference of the ring waveguide core 1A, and including an inner doped-silicon area or an inner silicide area that is provided in a slab section inward of the rib section; an outer circumference electrode line 4 provided along an outer circumference of the ring waveguide core 1A, and including an outer doped-silicon area or an outer silicide area that is provided in a slab section outward of the rib section; a modulation drive circuit 5; and a heater drive circuit 6. The modulation drive circuit 5 and the heater drive circuit 6 are connected to each of the inner circumference electrode line 3 and the outer circumference electrode line 4 so as to supply a modulation electric signal to the inner circumference electrode line 3 and the outer circumference electrode line 4 and so as to flow a heater current circumferentially, respectively. |
