Nonlinearity Effect on Multiwavelength fiber laser based on Sagnac loop mirror interferometer

Abstract

This paper demonstrates a multiwavelength fiber laser (MWFL) with erbiumdoped fiber amplifier (EDFA) as gain medium and Sagnac loop mirror interferometer as filter. Stable and flat lasing spectrum was achieved when highly nonlinear fiber (HNLF) was inserted into the laser cavity. The number of lasing lines and extinction ratio (ER) was directly influenced by EDFA gain where at maximum setting, 14 lasing lines with ER of 19 dB were generated. The stable and flat spectrum achieved spanned about 1.6 nm. This is due to the induced intensity dependent loss mechanism in the cavity by adjusting the half-wave plate of the polarization controller in combination with the HNLF. The MWFL output showed peak power variation of about 2.1 dB within 100 minutes of observation time.

Tunable and Switchable Multi-Wavelength Erbium-Doped Fiber Laser Based on Composite Structure Filter

“…To solve these problems, people have proposed various methods, such as inserting the frequency shift devices, using optical fiber filters, adding wavelength or intensity dependent loss (PDL) structures, and using the high nonlinear effect of optical fiber [4,5]. Because the comb filter has simple structure and flexible design, researchers often use Sagnac loop mirror (SLM) interferometer, Faby-Perot (FP) filter, Mach-Zehnder interferometer (MZI), Lyot filter and others to make multi-wavelength lasers [6]. Lv et al used a fiber filter composed of a section of three core photonic crystal fiber (TCPCF) and a section of multimode fiber (MMF), and proposed a tunable C-band and L-band 1-3 wavelength EDFL [7].…”