MULTIPLE-PHASE-SHIFT SUPER STRUCTURE GRATING DBR LASERS

This paper reports on broad-range wavelength tuning characteristics of DBR lasers which make use of a newly proposed multiple-phase-shift su per structure grating (SSG). The reflection characteristics of the SSG reflector are analyzed theoretically. We found that the SSG reflector has periodic sharp reflection peaks each with high reflectivities thu s making it a suitable wavelength selective reflector for single-mode lasers. The expected characteristics were evident in multiple-phase-sh ift SSGs fabricated using a new method which involves multiple-phase-s hift insertion. DBR lasers with multiple-phase-shift SSGs were fabrica ted and their wavelength tuning characteristics were studied. The maxi mum tuning range is 105 nm in the single longitudinal mode under a CW condition. Dynamic single mode operation was also observed throughout the tuning range.