| 摘要 |
PURPOSE:To obtain a single longitudinal mode laser easily by forming a higher diffraction grating at a position where the internal reflecting section of an IRI laser must be installed. CONSTITUTION:An SiO2 insulating film is shaped onto an n-InP substrate 1, an opening is formed at a location where an internal reflecting section must be shaped, and a pattern for a secondary diffraction grating at pitches of approximately 3700Angstrom is formed onto a resist through a two luminous-flux interference exposure method using an He-Cd laser. The secondary diffraction grating is shaped through etching by a bromine group mixed acid after post-baking, and the resist and the SiO2 insulating film are removed, thus forming the secondary diffraction grating in the internal reflecting section 2. An N-InGaAsP waveguide layer 3, an InGaAsP active layer 4 and an InGaAsP buffer layer 5 are grown successively onto the substrate 1 by first growth, a stripe composed of a resist is left on the layer 5 through photolithography, and a first growth layer is etched while employing said resist as a mask. A p-InP layer 6, an n-InP layer 7, a p-InP layer 8 and a p-InGaAs cap layer 9 are grown by second growth. |
