ASYMMETRIC Y-BRANCH TUNABLE SEMICONDUCTOR-LASER WITH 1.0 THZ TUNING RANGE

Tunable semiconductor lasers are crucial for wavelength division multiplex (WDM) multichannel optical communication systems. The tuning range of the traditional tunable lasers using distributed Bragg reflection is limited by the small refractive index change that can be induced in semiconductors. In this letter we report the design, fabrication, and characteristics of a novel asymmetric Y-branch (AYB) tunable laser. By geometrically leveraging the index change in these laser structures, we demonstrate, using a single current control, a discrete tuning range as large as 1.0 THz, access to 24 frequency channels, and tuning rates in excess of 100 Gz/mA. Such AYB lasers appear promising for applications requiring wide tuning range, fast electronic frequency access, and simple low current control.