Date of Award

1-1-2010

Thesis Type

phd

Document Type

Thesis

Divisions

science

Department

Dept of Physics

Institution

University of Malaya

Abstract

A thorough study on Bismuth-based Erbium-doped fiber (Bi-EDF) is presented for wide-band amplifiers and multi-wavelength fiber laser applications. This fiber allows high Erbium ions concentration to be doped without a significant concentration quenching effect. The high refractive index characteristic in the Bi-EDF has broadened the emission spectrum of Erbium ions to achieve a broader gain spectrum up to extended L-band region compared to normal silica-based Erbium-doped fiber (EDF). The Bi-EDFA performances have been investigated in terms of power conversion efficiency (PCE), quantum conversion efficiency (QCE), gain and noise figure. The highest QCE and PCE for a 215 cm long of Bi-EDF are estimated to be approximately 23.7% and 25.7%, which is obtained at 1605 nm. With bi-directional pumping, the maximum gain of 34 dB is obtained at approximately 1570 nm. The operation of the bi-directional Bi-EDFA covers from C-band to the extended L-band regions. Furthermore, various configurations on the multi-wavelength fiber lasers have been proposed and demonstrated using the Bi-EDF as both the linear and nonlinear effects. Nonlinear effects such as the stimulated Brillouin scattering (SBS) and four-wave mixing (FWM) are used in the fiber lasers to generate multi-wavelength comb lines. The Brillouin Erbium fiber laser (BEFL) is able to produce a stable comb with 50 lines at extended L-band region using only a Bi-EDF as the gain medium. The multi-wavelength fiber laser has also been demonstrated for the first time based on a Bi-EDF assisted by a FWM process. The estimation of the nonlinear parameters of Bi-EDF was also proposed based on the FWM effect. With a simple ring cavity, the laser generates more than 10 lines of optical comb with a line spacing of approximately 0.41nm at 1615.5 nm region using 146 mW of 1480 nm pump power.

Note

Thesis submitted in fulfillment of the requirement for the degree of Doctor of Philosophy

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