Title :
New high-resolution positive and negative photoresist method for λ/4-shifted DFB lasers
Author :
Okai, M. ; Tusji, S. ; Hirao, M. ; Matsumura, H.
Author_Institution :
Hitachi Ltd., Central Research Laboratory, Kokubunji, Japan
Abstract :
High-resolution positive and negative photoresists were used to fabricate λ/4-phase-shifted corrugations by holographic exposure. To avoid mixing these photoresists, cyclised polyisoprene was used as a midlayer. The shape and depth of the corrugations on the positive and negative photoresist regions were almost the same. Single-mode operation at the Bragg wavelength was confirmed in lasers with the corrugation.
Keywords :
distributed feedback lasers; holography; optical modulation; photoresists; semiconductor junction lasers; Bragg wavelength; DFB lasers; InP substrate; cyclised polyisoprene; holographic exposure; negative photoresist; phase shifted corrugations; positive photoresist; semiconductor laser; single mode operation;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19870271
