| 摘要 |
PURPOSE:To control the refractive index of a semiconductor optical waveguide and to lessen dispersion by forming an optical waveguide layer of a material which is substantially transparent in a use wavelength band, has a specific absorption and has a lattice constant nearly equal to. the lattice constant of the material of a clad layer. CONSTITUTION:This semiconductor optical waveguide is composed of an (on) type InP substrate 1, the optical waveguide layer 2 consisting of the semiconductor material having the absorption of >=10<3>cm<-1> in coefft. of absorption in the wavelength band of 3 to 15mum and having the lattice constant nearly equal to the lattice constant of Ink, an active layer 3 for causing laser oscillation by applying a gain to light of the wavelength 1.3 to 1.56mum, an optical modulator layer 4 for making mode lock action by applying modulation to light of the wavelength 1.55mum, a (p) type InP layer 5, p type electrodes 6, 7, an n type electrode 8 and a high reflection film 9. Namely, at least the optical waveguide layer of the optical waveguide is formed of the material which is substantially transparent in the use wavelength band, has the absorption of >=10<3>cm<-1> in coefft. of absorption in the wavelength band longer than the band and has the lattice constant nearly equal to the lattice constant of the clad material layer. |
