Switchable multi-wavelength erbium-doped fiber ring laser based on a tapered in-line Mach–Zehnder interferometer

Abstract

In this paper, a switchable multi-wavelength erbium-doped fiber ring laser based on a tapered in-line Mach-Zehnder interferometer is proposed. The in-line Mach-Zehnder interferometer is fabricated by splicing a large-core fiber between two segments of single mode fibers, in which the first splicing point is tapered and the second splicing point is connected directly. By carefully rotating the polarization controller, switchable single-, dual-, triple-and quadwavelength lasing outputs can be obtained with a side mode suppression ratio higher than 50 dB. The maximal peak power difference of multi-wavelength lasing is 3.67 dB, demonstrating a good power equalization performance. Furthermore, the proposed laser is proven to be very stable at room temperature. The wavelength shifts and peak power fluctuations are less than 0.02 nm and 1.3 dB over half an hour. In addition, stable quintuplewavelength lasing with a side mode suppression ratio higher than 50 dB can also be realized when the filter length is changed.

A kind of multiwavelength erbium-doped fiber laser based on Lyot filter

“…The SNR exceeded 50 dB, and the power fluctuation was lower than 1.3 dB. [20] As mentioned above, the multiwavelength tunable fiber lasers is usually realized by techniques such as the Lyot filter interferometer, Mach-Zehnder interferometer (MZI), nonlinear fiber loop, and mismatch fiber structure. The fiber laser spectrum characteristics are determined by the filter components, and it is difficult to realize a better filtering effect with a flexible interferometer comb spectrum, which results in the disadvantage of being less compact.…”