Improved optical performance in circular-grating distributed feedback nanoplasmonic lasers

Abstract

Abstract Optical modes control has been driven from vertical cavity surface emitting lasers (VCSELs) applications with multi-mode operation such as optical fiber communication or optical sensing. Optical gain materials coupling with optical resonators provides an effective way to tunning the optical mode of VCSELs. In this paper, a kind of nanoplasmonic laser was designed by using semiconductor nanorods array coupled optically with a distributed feedback circular grating. In this device, the mode field was cooperatively controlled by the confinement of surface plasmon around the nanorod cavity, and the spatially tune with the distributed feedback circular grating. Based on the physical model, the optimal device design with excellent lasering performance was achieved through a complete optimizing numerical simulation with multiple effects. The monochromatic circular grating distributed feedback nanoplasmonic laser functions the optimum lasing performance with a single-longitudinal mode peak at 511.2 nm, 3 dB line width of 1.98 pm, a side-mode rejection ratio of 45 dB, and a threshold current of 124 mA. A six-fold rotational symmetric far-field mode corresponding to the third-order Laguerre Gaussian azimuth mode was demonstrated by the distributed feedback circular grating. This work paves a fundamental way for the mode engineering design of novel nanolaser in the technical applications of optical communication, sensing and integrated photonics.