University of Connecticut

Events Calendar

PhD Defense

Tuesday, April 3, 2018
2:30pm – 4:30pm

Storrs Campus
IMS 159

Xiang Zhang, Department of Physics, University of Connecticut

Study of Supercontinuum and High Repetition Rate Short Pulse Generation

The rapidly increasing data traffic nowadays has benefited a lot from the dramatic progress of optical telecommunications such as dense wavelength division multiplexing (DWDM) and time-division multiplexing (TDM), which employ broadband light source and high-repetition ultrashort optical pulse respectively to carry information in optical fibers. High speed all optical data processing and switching components will also be important in future fiber-optic communication systems since conventional electro-optical parts have reached their bottleneck both speed-wise and efficiency-wise. In this PhD thesis work, I propose a dispersion varying scheme realized by non-uniformly tapering fibers or waveguides to enhance supercontinuum generation. The physical mechanism to generate broadband continuum such as dispersion, nonlinearity, and soliton dynamics have been explained. Numerical demonstration has been done in both lead silicate microstructured optical fibers and chalcogenide planar waveguides. A fiber ring laser system with rational harmonic mode-locking and nonlinear polarization rotation of a highly nonlinear photonic crystal fiber has been designed and experimentally demonstrated to generate stable ultrashort optical pulse train at a repetition rate of 30 GHz with low signal noise ratio. All-optical encryption operating at 250 Gb/s using optical Boolean logical gates based on the two-photon absorption (TPA) in bulk semiconductor optical amplifiers (SOAs) has been demonstrated. The effects of TPA on the performance of optical logical gates based on quantum-dot SOAs has also been explored. TPA can improve the operating speed up to 320 Gb/s.

Contact:

Prof. N. Dutta

Physics Department (primary)

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