Tunable semiconductor lasers are key components in future optical fiber networks. Typical distributed Bragg reflector (DBR) tunable lasers, such as SGDBR laser and DS-DBR laser, have the advantages of a wide wavelength tuning range, a high side mode suppression ratio (SMSR) and a high wavelength switching speed. However, the fabrication processes of those structures are complicated, in which regrowth processes and rigorous active-passive integration are involved. In the past few years, a new structure fabricated by etching discrete perturbing slots into the Fabry-Perot laser ridge waveguide was proposed, and it was also referred to as the slotted Fabry-Perot (SFP) laser. The merits of this structure are simple fabrication and then low cost, since there is no epitaxial regrowth in the fabrication process and only standard photolithography is required. Thus, this slot structure is attractive for development of a new type of tunable laser with low-cost.
Prof. Yonglin Yu’s group from Wuhan National Lab for Optoelectronics (WNLO), cooperating with Prof. L. P. Barry’s group from Dublin City University, studied on the three-section slotted Fabry-Perot (3s-SFP) tunable lasers. A time-domain traveling-wave (TDTW) model was developed to simulate the 3s-SFP lasers. Simulation results achieved are in good agreement with the experimental measurements. This work not only reveals the lasing characteristics and the tuning mechanism of the 3s-SFP lasers, but also provides guidance for designing and optimizing the 3s-SFP laser.
This work, published in IEEE Journal of Selected Topics in Quantum Electronics (vol.15, No.3, Sep/Oct, 2013),was supported in part by the International S&T Cooperation Program of China, in part by National Natural Science Foundation of China, in part by Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP), in part by Science Foundation Ireland Principal Investigator Program and Enterprise Ireland Innovation Partnership Program.
Fig.1. Structure of the 3s-SFP laser.
Fig.2. Superimposed tuning spectra of eight different modes.