Channel-spacing-tunable multi-wavelength fiber ring laser with hybrid Raman and Erbium-doped fiber gains

Abstract

A multi-wavelength fiber ring laser of tunable channel spacing is proposed by employing an optical variable delay line (OVDL) in a Mach-Zehnder interferometer. Stable lasing is achieved at room temperature with the hybrid gains of a single mode fiber (as the Raman gain medium) and an Erbium-doped fiber (EDF) in a ring structure. The channel spacing of the present multi-wavelength fiber ring laser can be continuously tuned by adjusting the computer-controlled OVDL.

Overview of Nonlinear Optics

“…Continuously tunable channel spacing can be achieved with a hybrid of an erbium-doped fiber laser that gives high power conversion efficiency and a fiber Raman laser that has a large lasing bandwidth, both placed in an all-fiber ring cavity (Chen, 2007); stable multi-wavelength lasing has been observed over 24 wavelengths.…”

Tunable Fibre Lasers Based on Optical Amplifiers and an Opto-VLSI Processor

“…However, they usually suffer from performance instability and difficulty in free spectral range (FSR) control. A multi-wavelength fiber ring laser of tunable channel spacing has been proposed by employing an optical variable delay line (OVDL) in a MachZehnder interferometer (D. R. Chen et al, 2007). The channel spacing of the present multiwavelength fiber ring laser can be continuously tuned by adjusting the computer-controlled OVDL.…”

“…The lasing wavelengths can be switched individually by two PCs because the nonlinear polarization phenomenon based on the NOLM induces the polarization-dependence loss and the birefringence-induced wavelength-dependent loss in the laser ring cavity, which can determine the total loss of the laser ring cavity. Stable multiwavelength lasing has been achieved at room temperature with the hybrid gains of a Raman gain medium and an Erbium-doped fiber in a ring structure (D. R. Chen et al, 2007). The multi-wavelength fiber laser employing Raman and EDF gains increases the lasing bandwidth compared with a pure EDF laser and the power conversion efficiency compared with a pure fiber Raman laser.…”

Tunable multiwavelength erbium-doped fiber laser based on nonlinear optical loop mirror and birefringence fiber filter

“…However, the spectral behavior of most tunable comb filters tends to change the whole spectrum, or all channel transmissivities in the tuning process, which results in the simultaneous change in multiple output characteristic parameters. For example, the change in number of lasing lines is always accompanied by change in channel spacing [10,12] or peak location [15]. Independent control over number of lasing lines without affecting channel spacing is challenging.…”

“…There are also two types of tunable comb filters that have been studied for this purpose. The first type of filter is based on the tunable periodic comb filter, including birefringence fiber filter (BFF) [9], MachZehender interferometer (MZI) [10,12], superimposed Abstract A tunable multiwavelength erbium-doped fiber laser (MWEDFL) based on nonlinear optical loop mirror (NOLM) and tunable birefringence fiber filter (BFF) is proposed and demonstrated. By combination of intensitydependent loss modulation induced by NOLM and pump power adjustment, the proposed laser can achieve independent control over the number of lasing lines, without affecting other important characteristics such as channel spacing and peak location.…”