Tunable External Cavity Semiconductor Laser Based On Micro-ring Resonator In SOI

With the further development of optical communication technology, semiconductor laser as the light source plays an important role in the optical fiber communication system and optical switching system. Compared to the traditional semiconductor laser, external cavity laser has the more narrow linewidth, larger tuning range, the smaller the chirp and excellent spectral characteristics. So it has been a hot research.In this thesis, I proposed an external cavity tunable laser based on thermally-tuned silicon double ring resonator. The thesis mainly introduces the thermally-tuned cascaded double rings resonator and the design of collimation optical path of external cavity.Firstly, this thesis introuduce the basic theory of the micro-ring resonator, the transfer function of the micro-ring resonator and the solid heat transfer theory. The optical field distribution in SOI waveguide is analyzed in detail. Silicon has higher thermo-optic coefficient, which can be applied to the thermally-tuned cascaded double rings resonator. The tuning performance of cascaded double rings resonator is analyzed. Owing to Vernier effect, the tuning range is enlarged, as well as increases the range of the wavelength shift and the thermal tuning efficiency.Then the thesis describes the fabrication process of thermally-tuned cascaded double rings resonator and micro-heater in detail. The test platform of cascaded double rings resonator is built; then I introduces the whole test process and the test results.Finally, the thesis introduces the details of the characteristics of the graded-index lenses. A collimation light path can be established by using two graded-index lenses. Meanwhile, thermally- tuned cascaded double ring sresonator cavity and FP cavity can be combined. External cavity laser is established, which can achieve a narrow linewidth output.