| 摘要 |
PURPOSE:To realize a monoaxial mode oscillation over a wide temperature range by a method wherein a substrate whose coefficient of thermal expansion is smaller than that of a laminated structure is used and a groove crossing a resonator of the laminated structure is made until it reaches the substrate. CONSTITUTION:When GaAs is grown on Si, there exists a lattice unconformity; a coefficient of thermal expansion for Si is 2.4X10<-6>deg<-1> while that for GaAs is 5.8X10<-6>deg<-1>; as a result, a distortion is generated at the interface. Considering this, a Ge intermediate layer 2 to relax the distortion is grown with a thickness of 0.4 mum between the Si and the GaAs by an MOCVD method. A groove 15 which cuts off a resonator at a part of the resonator is etched by using a 3-layer resist material by an RIBE method so as to form a mirror surface. The width of the groove is to be 20 mum and its depth is to reach an Si substrate 1. Because the coefficient of thermal expansion of the Si of the substrate is small as compared with that of the GaAs of a laminated structure, the temperature characteristic of the peak of an envelope curve of a laser oscillation spectrum can be made small; a monoaxial mode oscillation is obtained over a temperature range of up to 60 deg.C including the room temperature.
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