Novel semiconductor lasers and integrated photonic devices

Novel design concepts, simulations and experimental results on semiconductor lasers and integrated photonic devices are presented, for both telecom and biomedical applications. It is shown that the Vernier effect can be used to increase the tuning range of a digitally wavelength-switchable semiconductor laser, and to increase the sensitivity of passive and active waveguide sensors. The wavelength switchable laser based on V-coupled cavity has a large tolerance on the accuracy of the setting current. For the middle 50% of the current range corresponding to a wavelength channel, the wavelength varies by only +/- 0.01nm from the set value for 0.8nm channel spacing and the SMSR is maintained above 38dB. Wavelength switching over 8 consecutive channels is experimentally demonstrated using a single electrode control. The wavelength shift sensitivity of a waveguide sensor based on two cascaded microring resonators with Vernier effect can reach 1300nm/RIU, over an order of magnitude higher than a single ring sensor. A monolithic integrated intracavity biosensor based on V-coupled cavity laser is also proposed and analyzed. By simply detecting the power ratio of two output ports, a refractive index sensitivity in the order of 10(-8) RIU can be achieved thanks to the intracavity sensing mechanism and the Vernier effect.