| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor laser device which can perform an active mode synchronizing operation of pulse light shaped by a saturable absorber. SOLUTION: In a plan view (A) of a semiconductor laser when viewed from above, a P-side electrode 46, an InP block layer 28 and a control layer 32 are formed. The Fig. (B) is a longitudinal cross-sectional view taken at the height of a waveguide layer, in (C) which a waveguide region 11 is made of InGaAsP (band gap of 1.3μm), active regions (D) 16 and 17 are made of the same material but different compositions with a band gap of 1.5μm, and a planar waveguide region 12 is made of nonlinear optical material and inserted perpendicularly to a wave guiding direction. The active region 16 and 17, which form a gain part 18, form a resonator 20 together with a waveguide part 14 of the regions 10, 11 and 12. In the resonator 20, strong light is concentrated in a center of the waveguide of the region 12 under influence of saturable effect, while weak light is dispersed from the waveguide regions 10 and 11 into the region 12 under influence of diffraction effect. As a result, shaped short pulse light is lased in synchronism with a passive mode.
|
