NOVEL TUNABLE SEMICONDUCTOR-LASERS USING CONTINUOUSLY CHIRPED DISTRIBUTED-FEEDBACK GRATINGS WITH ULTRAHIGH SPATIAL PRECISION

We present experimental and theoretical results obtained from a new ty pe of tunable two- and three-section semiconductor distributed feedbac k (DFB) laser using tailored chirped DFB gratings. The chirped grating s are defined by bent waveguides on homogeneous grating fields with ul trahigh spatial precision using bent waveguides. Arbitrary and continu ous chirping functions can be obtained by appropriate mathematical ben ding functions. Our method is applied for tunable lasers with optimize d bending shapes revealing a considerably enlarged wavelength tuning r ange of 5.5 nm without wavelength gaps. (C) 1994 American Institure of Physics.