Numerical research on a dual-mode sampled-grating quantum-dot-based InP/InGaAs/InGaAsP DFB laser for W-band RoF application

In this paper, we design and simulate an InP/InGaAs/InGaAsP dual-mode sampled Bragg grating quantum-dot (QD) based distributed feedback (DFB) laser constituted with alternating grating and FP sections in both COMSOL Multiphysics 4.3 and VPI Transmission Maker 8.9. Sampled grating (SG) reflection spectrum is simulated based on transfer matrix method. 2D and 3D optical mode analysis is implemented in COMSOL. In theory, the Coupled-Mode Equation (CME) is used to numerically description the dynamic behavior of this DFB laser. At the meantime, QD laser space and mode model is simulated and verified in COMSOL Multiphysics 4.3. The design QD Laser emitting wavelength is 1550 nm. The mode spacing in W-band millimetre-wave domain (75GHz) and side-mode-suppression-ratio (SMSR) as high as 50dB are achieved. Finally, a spectral pure and stable 75GHz mm-wave signal with 3-dB linewidth of 10MHz is observed on an electrical spectrum analyser after beating on a wideband photodiode in VPI Transmission Maker 8.9 software.