Numerical Analysis on Thermal Tuning Efficiency and Thermal Stress of a Thermally Tunable SG-DBR Laser

Abstract

Thermally tunable sampled grating distributed Bragg reflector (SG-DBR) lasers are very attractive for applications of optical coherent systems, where light sources with narrow linewidth are key requirements. In this paper, we focus on the thermal tuning efficiency and the thermal stress field of such lasers. The influence of a thermal isolation (air trench) design on the tuning efficiency of the laser is analyzed by using a thermal model based on the finite-element method (FEM) at first. The thermal tuning efficiency is found to be tenfold improved if the air trench is used. Influences of the air trench geometry configurations on temperature and thermal stress field are then examined in detail. Simulation results indicate that the most dangerous positions that can crack always appear at the output port and the corner of the air trench structure contact with the n-InP layer. The air trench geometry configuration of an SG-DBR laser is finally optimized (with a width of 70 m and a thickness of 1 m) to ensure the reliability and the quasicontinuous wavelength tuning range of the device at the same time. With the optimized design, by using a developed temperature-dependent transfer matrix method-based optical model, optical output characteristics of the thermally tunable SG-DBR laser are demonstrated, including the output wavelength for the tuning range (1525-1585 nm covering C band) and the linewidth for all the channels (several tens to several hundreds of kilohertz). The simulated results have been found to be in good agreement with the experimental measurements previously reported, which are helpful to the thermal management and the design optimization of such devices.

Athermal Tuning for a Two-Section, All-Active DBR Laser With High-Order Grating

“…Tuning maps are generally presented for SG-DBR and other widely tunable lasers. An earlier work from our group in [28] offers a comparative study with tuning maps for 3-section DBR and 4-section SG-DBR lasers showing a noticeably more linear tuning effect when varying currents in the front and rear mirror sections [29]. Notably in these types of lasers, the overall redshift in wavelength due to thermal effects for increasing front grating current is comparable to that of the all-active DBR laser demonstrated in Fig.…”

EAM Integrated Widely Tunable DBR Lasers Based on InGaAlAs/InP MQWs

“…For wavelength division multiplexing (WDM) systems, which increase the data capacity by transmitting multiple different wavelengths at the same time, a number of these devices each having a different wavelength have to be used, which would inevitably increase the system's construction costs. Distributed Bragg Reflector (DBR) lasers have been gaining increasing attention due to their simple tuning method and easy fabrication process, as compared to the external cavity lasers [8] and sampled grating DBR lasers [9]. High-speed modulated DBR lasers are promising low cost devices to meet the demands for high capacity WDM optical communication systems [10,11].…”

Influence of spectral splicing on the spatial resolution of optical frequency domain reflectometry

“…ECTLs are susceptible to interference as well as large in size and weight because of the mechanical scanning structure [12]. A distributed Bragg reflector (DBR) laser is a mature light source in the field of optical communication, with the advantages of small size, no mechanical scanning, easy integration, and low cost [13]. However, due to the mode hopping of the DBR laser, the wavelength can only be continuously tuned in segments.…”