| 摘要 |
PURPOSE:To shift the phase of light propagating within laser in reference to diffraction grid and to simplify adjustment of amount of phase shift by bending stripe structure which forms laser. CONSTITUTION:After coating the entire surface of an n-type InP substrate 1 with resist, primary diffraction grid pattern is marked using HeCd laser beam, chemical etching is performed, and then a diffraction grid 5 is formed. An n-InGaAsP layer 2, an InGaAsP active layer 3, and then an InGaAsP buffer layer 4 are lamination-formed on this substrate 1 in sequence. Then, after performing patterning using a mask of bent pattern, mesa etching is performed to obtain a stripe with bent part at the center. Then, an InP layer 11 is allowed to grow again and an InGaAsP layer 6 is laminated on it. Then, an SiO2 layer 7 with a window is built up and a diffusion region 10 is formed by diffusing Zn so that it reaches the InP layer 11. After that, electrodes 8 and 9 are deposited, is turned into alloy, is divided into chips by cleavage, and SiN is built up on the cleavage surface. It allows a phase shift type DFB laser to be produced easily without using a complex resist coating process. |
