To implement a practical WDM passive optical network, it is essential to develop cost-effective WDM light sources. Recently, a spectrum-sliced fiber amplifier light source has been proposed for this purpose. In these light sources, the high-power amplified spontaneous emission from an erbium-doped fiber amplifier is spectrum-sliced into many channels using an integrated optic WDM demultiplexer. However, despite of high-power amplified spontaneous emission available in erbium-doped amplifiers, the output power of each channel is still quite limited due to the inherently large spectrum-slicing losses.
In this thesis, we investigate the optimum architecture of spectrum-sliced fiber amplifier light source to obtain maximum output power per channel. In particular, we evaluate the performance of the spectrum-sliced light sources based on three basic architectures (single-stage amplifier, two-stage amplifier, and two-stage amplifier with an inter-stage bandpass filter). We assume that the maximum pump power can not exceed 140mW at 1480nm. We analyze both the effects of fiber length and pump power. The optimum ratios of fiber lengths and pump power between the first and second stage have also been analyzed when the light source is based on a two-stage amplifier. The results show that the spectrum-sliced fiber amplifier light source based on two-stage amplifier with an inter-stage bandpass filter provides higher output power per channel than the other sources based on single-stage and two-stage amplifier. With the pump ratio of 15:125 and the second-stage EDF length of 50m, the maximum output power per channel (-7.5 dBm/0.1nm @ 13nm transmission bandwidth) is obtained in two-stage architecture with optical bandpass filter. We also demonstrate the output power equalization between channels by using an inter-stage fiber bragg grating filter. In this architecture, the output power per channel is maximized (-5.2 dBm/0.1nm @ 13nm transmission bandwidth) with the output power difference of less than >1dB.
