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|Title: ||Multiwavelength Brillouin/Erbium fiber laser assisted by bismuth-based erbium-doped fiber amplifier|
|Authors: ||Nurul Shahrizan Shahabuddin|
|Keywords: ||Multiwavelength Brillouin|
|Issue Date: ||2009 |
|Publisher: ||University Malaya|
|Abstract: ||The thesis focuses on the exploitation of nonlinear effects in single-mode fiber (SMF), mainly the stimulated Brillouin scattering (SBS) to generate multiwavelength signal in a Bismuth-based Brillouin/Erbium fiber laser (BEFL). A 2.15 m Bismuthbased Erbium-doped fiber (Bi-EDF) with Erbium ion concentration of 3250 wt. ppm. Is used as a linear gain medium in the BEFL . The characteristic of the Bismuth-based Erbium-doped fiber amplifier (Bi-EDFA) is studied. The amplifier exhibits gain in 1565 to 1600 nm region when the Bi-EDF is pumped with two laser diodes of wavelength 1480 nm with 100 mW pump power each. Double-pass Bi-EDFA shows better gain performance but higher noise figure than single-pass Bi-EDFA. Thus, single-pass Bi-
EDFA is preferred to be employed in the BEFL system.
In this thesis, the BEFL signal is generated in ring and linear cavities with channel spacing of 0.09 nm. The injected Brillouin pump (BP) wavelength and power as well as the power of 1480 nm pumps and effective cavity loss in the cavity exhibited great effect on the number of wavelengths and output power of the generated wavelength comb. The linear cavity BEFL exhibits a lower threshold power compared to the ring configuration. Linear cavity shows improvement on the number of lines generated. Three linear cavity designs are demonstrated. The third linear cavity BEFL with lower cavity loss could generate up to 50 lines compared to 13 Stokes and anti- Stokes lines generated by ring cavity BEFL. The stable output laser comb of 50 lines is obtained at a BP wavelength of 1568.2 nm and BP power of 5 dBm and two 1480 nm pumps power at 120 mW. The number of lines increases as the BP power increases from 3 to 8 dBm. The Stokes lines are generated as long as the gain is sufficient to support the cascading process.
The multiwavelength BEFL signal has potential applications in wavelength division multiplexing (WDM), optical fiber sensor system, optical component testing and spectroscopy applications.|
|Description: ||Dissertation (M.C.S.) -- Faculty of Science, University of Malaya, 2009.|
|Appears in Collections:||Masters Dissertations : Science|