Rajandeep Singh

Optimized hybrid Silica TDFA-RAMAN wideband amplifier yielding flat gain in S-Band

For S-Band wavelength division multiplexing (WDM) systems Silica based Thulium doped fiber amplifier (TDFA) is a main amplifying media. But the gain provided by TDFA alone is low and not flat in entire S-Band. In this paper, Raman amplifier in hybrid configuration with TDFA has been used to flatten the gain. The gain curves for the TDFA alone are analyzed and optimized for TDFA length and Thulium doping concentration then the overall gain of hybrid configuration is flattened by controlling the gain of Raman amplifier. It has been observed that fairly flat gain curve (5dB variation) in S-band region (1460 nm to 1500 nm) is achieved, maximum gain of 31.1dB at 1470nm and lowest gain of 26.1dB at 1500nm have been observed.

Evaluating the effect of doping concentration and doping radius on the gain of silica based Thulium doped fiber amplifier

Thulium doped fiber amplifier is the most capable amplifier candidate for the Wavelength Division Multiplexing (WDM) systems working in S-band. Fluoride TDFA (Thulium doped fiber amplifier) provide better gain characteristics than the silica TDFA because of relatively low phonon energy of Thulium in fluoride host. On the other hand Silica TDFA has many advantages over Fluoride TDFA. In this paper gain evaluation of silica TDFA for doping concentration 20ppm and 80ppm for varied doping radius from 0.3µm–1.3 µm has been done. The main objective of the paper is to find the TDFA parameters which yield better gain. It has been observed that with the triple pumping (1050nm+1400nm+800nm), the maximum gain of 29.63dB at 1470nm has been obtained for the 80ppm concentration with 0.7µm doping radius.