CONTROL OF LASING WAVELENGTH IN DISTRIBUTED-FEEDBACK LASERS BY ANGLING THE ACTIVE STRIPE WITH RESPECT TO THE GRATING

We proposed and demonstrated a new and very simple technique of varying the lasing wavelength of distributed feedback (DFB) lasers with the need for fabricating gratings with different pitches. This is accomplished by angling the active stripe at an oblique angle with respect to the axis of the grating lines. This technique should be particularly suitable for fine tuning of lasing wavelength, and it eases the stringent demand on precise control of absolute grating pitches. It should be useful and important for dense (wavelength division multiplexing (WDM) applications and monolithic integration of multiwavelength DFB lasers.