No abstract

A tuneable single longitudinal mode fibre ring laser with dual-taper fibre filter is proposed and experimentally demonstrated in this paper. The single longitudinal mode operation, and power limitations for a Mach-Zehnder interferometer filter generated from a single mode fibre, are verified for the first time. Incorporating an in-line taper fibre Mach-Zehnder interferometer filter inside the laser ring cavity causes a spatial mode beating interference, resulting in a passive narrow band filter with the ability to generate stable single longitudinal modes. The single longitudinal mode achieves a side mode suppression ratio of more than 60 dB using low pump power. The tuneability of the fibre laser ranges from 1525 to 1562 nm using a passive band pass filter. A study of the stability and limitation of the single longitudinal mode in the Mach-Zehnder tapered fibre is also presented.

No abstract

No abstract

Functionality improvement of a non-linear semiconductor optical amplifier for multiwavelength generation is reported. A microfiber Mach-Zehnder interferometer (MMZI) is incorporated to enhance the multi-wavelength generation performance in terms of optical signal-to-noise ratio (OSNR) and full-width-half-maximum linewidth. The proposed scheme offers better dynamic functionality, with flexible tunable and switchable properties. Incorporating the MMZI causes spatial mode beating interference, resulting in narrow bands and power-efficient modes. Tunable and switchable octuple wavelength is demonstrated using non-linear polarization rotation (NPR), with frequency separation with respect to the free spectral range of the implemented MMZI over a greater than 30 nm span. The NPR effect is induced to suppress mode competition within the homogeneous broadening linewidth of the employed semiconductor optical amplifier.