In this paper, a new kind of tunable distributed Bragg reflector (DBR) laser based on the step-chirped sampled Bragg grating (SBG), has been proposed and studied. Based on analysis and simulations, it has been shown that a comb-like reflectivity spectrum with flat envelop covering over 40 nm can be realized with the proposed structure.
Static characteristics of the DBR laser, including the wavelength tuning range, output power, side-mode suppression ratio (SMSR), and L-I curves, are stimulated. The tuning range of 40 nm can be obtained and the laser threshold current is around 12 mA.