Multi-wavelength laser operation and pulse propagation using nonlinear fibers

Date of Completion

January 2010


Physics, Optics




In future fiber-optic communication systems, it will be important to increase the transmission capacity. Wavelength-division-multiplexing (WDM) is a technology which can expand the bandwidth of already existing fiber transmission networks by multiplexing multiple optical carrier signals on a single optical fiber. However, current WDM network system uses a single laser source for each wavelength channel, requiring dedicated wavelength control and thermal management. This complexity comes at a significant cost. A very attractive solution to minimize the complexity is to use a multiwavelength laser source. In this PhD thesis work, we proposed and demonstrated various schemes of multiwavelength ring laser sources, which can be potentially used in future WDM systems. Stable optical dual wavelength mode-locked operation is achieved in a fiber laser by using nonlinear polarization rotation (NPR) in a highly nonlinear fiber (HNF) or gain distribution in a dispersion compensating fiber (DCF). In addition, a multiwavelength passively mode-locked laser is also demonstrated. Further research has shown that NPR can also be used to generate an amplitude-equalized dual-wavelength rational harmonic mode-locked fiber ring laser with a data rate up to 40 GHz per wavelength. In order to better understand the mechanism of pulse propagation in optical fibers, self-similar pulse generation and supercontinuum generation have been investigated. ^