High number of wavelength channels demonstrated by a widely tunable sampled-grating DBR laser

Abstract
A three-section sampled-grating DBR laser has been realised. It presents a 25 nm tuning range with an SMSR greater than 30 dB. For the first time with sampled reflectors, access to 22 wavelength channels is achieved thanks to discontinuous tuning among the five main reflection peaks of the comb-reflection spectra of the sampled gratings. Operation of this device under amplitude modulation is also discussed: an AM bandwidth greater than 2.5 GHz has been demonstrated.