Study Of GaN Based Semiconductor Optoelectronic Devices With Narrow Spectral Linewidth

GaN-based edge-emitting laser diode and light emitting diode(LED)are two kinds of important semiconductor optoelectronic devices.However,GaN-based edge-emitting laser diode with conventional Fabry-Perot resonator structure always operates in multi-longitudinal modes,and LED is characterized by a wide-band emission due to the wide spontaneous emission spectrum.These are not conducive to some applications where narrow linewidth is required.Aiming at the problem of wide emission spectrum in GaN-based edge-emitting laser diode and LED,the reaserch about GaN-based grating-coup led external cavity diode laser and resonant cavity light emitting diode(RCLED)have been carried out in this paper.Through the structural design and performance optimization of the devices,the narrowband emission with single longitudinal mode is realized.The main work is as follows:1.Study of GaN-based tunable grating-coupled external cavity semiconductor laser.Littrow-type and Littman-type grating-coupled external cavity lasers have been fabricated by employing a commercially available 520 nm high-power GaN-based edge-emitting green laser diode as gain device.The effect of grating diffraction efficiency on the output performance of the Littrow-type external cavity laser is analyzed.Meanwhile,the influence of different incident angles on the grating on the output performance of the Littman-type external cavity laser was studied.Finally,the performances of the two kinds of devices are compared and analyzed.2.Structure design and optical simulation of GaN-based RCLED.The GaN-based RCLED with metal mirror and dielectric distributed Bragg reflector(DBR)was designed and fabricated.The curves of reflectivity for dielectric DBRs with conventional structure and Fabry-Perot filter-structure were calculated respectively by theoretical simulation.Based on the light-emitting performance of the device without top mirror,the light-output performance of RCLEDs using DBR with different DBRs as the top-mirror was simulate by matlab software.3.Performance measurements and analysis of GaN-based RCLEDs.Based on the self-built multi-angle LED optical test platform,the performance of RCLEDs with conventional structure DBR and filter-structure DBR as top mirror were measured and analyzed respectively.Then,the performance differences between the two kinds of RCLEDs were compared.It is indicated that single longitudinal-mode emission can be realized when using 9 pairs filter-structure DBR as the top mirror.The spectral linewidth can be narrowed down to 0.6 nm,Apractical light source with low-cost and narrow linew id th is provided.