| 主权项 |
1. An optical semiconductor device comprising:
a laser oscillator on a semiconductor substrate; and an optical modulator on the semiconductor substrate, wherein the laser oscillator includes a pair of reflecting mirrors at least one of which is a loop mirror, and the loop mirror includes a loop waveguide and a plurality of first ring resonators serially inserted in the loop waveguide, wherein the optical modulator includes a plurality of second ring resonators connected in cascade along a modulator waveguide, wherein a transmission band width of the first ring resonator is set greater than a transmission band width of the second ring resonator. |
