Nearly-octave wavelength tuning of a continuous wave fiber laser

Abstract

The wavelength tunability of conventional fiber lasers are limited by the bandwidth of gain spectrum and the tunability of feedback mechanism. Here a fiber laser which is continuously tunable from 1 to 1.9 μm is reported. It is a random distributed feedback Raman fiber laser, pumped by a tunable Yb doped fiber laser. The ultra-wide wavelength tunability is enabled by the unique property of random distributed feedback Raman fiber laser that both stimulated Raman scattering gain and Rayleigh scattering feedback are available at any wavelength. The dispersion property of the gain fiber is used to control the spectral purity of the laser output.

High order cascaded Raman random fiber laser with high spectral purity

“…The far end of Raman fiber is angle cleaved to minimize the back reflection. The configuration of the RRFL has been detailed in [14].The randomly distributed Rayleigh scattering in the core of Raman fiber provides necessary feedback for the random laser action. For comparison experiments, a conventional FBG-based fiber oscillator at 1064 nm is built as well to pump the RRFL.…”

“…Wu et al reported a cascaded RRFL with output power amounts to 2.7 and 4 W for the first (1115 nm) and second (1175 nm) order Stokes waves, respectively [13]. Zhang et al demonstrated a 900 nm nearly-octave wavelength tunable random laser with up to the 10th order cascaded Raman scattering [14]. Recently, Lobach et al demonstrated a cascaded linearly polarized RRFL based on phosphosilicate fiber, getting 8 W output at 1262 nm and 9 W output at 1515 nm [15].…”

Passively spatiotemporal gain-modulation-induced stable pulsing operation of a random fiber laser

“…A random fiber laser (RFL), whose operation is based on the extremely weak Rayleigh scattering (RS) provided random distributed feedback (RDFB) and Raman gain in a section of passive fiber, has attracted increasing attention in the past decades for its special features of cavity-free, mode-free, and structural simplicity, and for its application potential in telecommunication and distributed sensing [1][2][3][4]. The recent developments of RFL mainly focus on the power scaling [5][6][7], polarization operating [8,9], wavelength tuning [10,11], linewidth narrowing [12][13][14], spectral coverage extending [15,16], application for frequency doubling [17], mid-infrared light source pumping [18,19], and so on [4].…”

Random Raman fiber laser based on a twin-core fiber with FBGs inscribed by femtosecond radiation

“…Moreover, such a broad wavelength tuning is possible with a single pump source operating around 1 μm, due to the efficient cascaded generation of higher-order Stokes waves. This is possible in a RDFB laser scheme, even in the absence of resonant cavities for each order [4,5], a condition which is necessary for the cascaded operation of conventional Raman fiber lasers. Even for highorder Stokes waves, the optical efficiency of pump-to-Stokes conversion is as high as ∼70% (for a quantum efficiency >80%) [4], thanks to the absence of intra-cavity elements (and their corresponding insertion losses) in a RDFB fiber laser.…”