Research on the Novel Bragg Gratings and Their Applications in Tunable Semiconductor Lasers

Bragg grating and a tunable semiconductor lasers is an important part of one of the all-optical communication network, which has provided a guarantee for the realization of a reconfigurable intelligent optical network. The same time, they are also the fiber optic sensing and measurement in the field of key devices in one. Bragg grating and tunable semiconductor lasers, by the widespread concern of the industry at home and abroad with a wide range of application prospects. The papers around the Bragg grating tunable semiconductor laser, expand the system and in-depth research, specific studies are as follows: (1) according to the Bragg grating Fourier transform theory, deduced sampled fiber grating, two Gaussian apodized sampled fiber the grating and intercalatum sampling fiber grating reflection spectrum envelope expression, and verify the accuracy of the expression by the transfer matrix method. Not only to analyze the impact of various parameters on the grating reflection spectrum envelope sidelobe detailed study of the changes in the temperature and stress on the reflection spectra sampled fiber grating. (2) with a phase shift between interpolation sampled fiber grating reflection spectrum envelope expression analyzes between interpolated samples with a phase shift of the phase shift of the neutron grating of the fiber grating, the length of the grating region, inserted between the length of the reflection spectrum of the envelope impact. Provides a theoretical basis for the design of the flat-topped interleaved sampled grating. (3) based on the Fourier transform of the linear invariance and reversible transformation, multi-reflection spectrum envelope concatenation technology. The technology can not only encrypt sampled fiber grating spectrum channel, but also to the physical structure of the grating space encryption. Using this technique, two new multi-reflection spectrum of Bragg grating - Digital cascaded grating, and continuous intercalatum sampling grating. Two novel Bragg grating can not only provide the top flat reflection spectrum envelope can also maintain high peak reflectivity grating. (4) combined linear laser transmission method and the equivalent cavity tunable sampled fiber grating external cavity semiconductor laser numerical simulation model. Simulate the static characteristics of the laser, such as: the threshold characteristics of PI curve, spectral linewidth lasing spectrum, static tuning characteristics and side-mode suppression ratio. Vernier tuning principles for the design of the external cavity tunable semiconductor lasers provide a theoretical basis. (5) through the theoretical simulation sampling fiber grating external cavity semiconductor laser tuning curve, side-mode suppression ratio and output optical power observed nonlinear phenomena that exist in all tunable semiconductor lasers, such as: tuning hysteresis side mode rejection ratio and the output optical power spectrum asymmetry. In order to analyze the causes of these nonlinear phenomena, the semiconductor nonlinear effects (such as: cross-gain modulation, cross-phase modulation, four-wave mixing) taking into account the theoretical model of the laser. Internal physical parameters and semiconductor four-wave mixing effect of these non-linear phenomena. Provides a theoretical basis for the study of the nonlinear mechanism of tunable semiconductor lasers inside. (6) In order to suppress the sampled fiber grating external cavity semiconductor laser tunable nonlinear effects in the laser external grating the introduced intercalatum technology and apodization technology. Sidelobe suppression can be non-linear phenomenon is suppressed to some extent, increase the bandwidth of the tuning of the tunable semiconductor laser. The technology processing intercalatum able sampled fiber grating external cavity tunable semiconductor laser tuning bandwidth of 18.4 nn. And in the entire tuning range, the optical power output of 10 dBm, side-mode suppression ratio of 40 dB. (7) to establish a theoretical model of the SG-DBR laser; The static characteristics of the SG-DBR laser. Through the establishment of the theoretical model and found that tunable semiconductor lasers reflecting facet with a stealth FP cavity is formed between the sampled grating. FP cavity of the invisible static characteristics of the SG-DBR lasers have a great impact, especially the tuning curve. (8) based digital cascade two grating design structure of the semiconductor material, a change to the grating period of the grating of the cascade; Another change the effective refractive index of the cascade grating. Both programs are able to get to the top of a flat reflection spectrum. Also proposed a method of making three embodiment: the holographic exposure, electron beam exposure, nanoimprinting. (9) proposed a novel tunable DBR laser - The digital cascade DBR laser. The simulation results show that the design was nearly 50 nm wavelength tuning range, and the entire tuning region, the side-mode suppression ratio up to 35 dB, the output power is maintained at about 10 dBm, and has a good balanced output optical power (0.6 dB), and the reflectance of the end face of the high tolerance.