Raman fiber lasers

Abstract

High-power fiber lasers have seen tremendous development in the last decade, with output powers exceeding multiple kilowatts from a single fiber. Ytterbium has been at the forefront as the primary rare-earth-doped gain medium owing to its inherent material advantages. However, for this reason, the lasers are largely confined to the narrow emission wavelength region of ytterbium. Power scaling at other wavelength regions has lagged significantly, and a large number of applications rely upon the diversity of emission wavelengths. Currently, Raman fiber lasers are the only known wavelength agile, scalable, high-power fiber laser technology that can span the wavelength spectrum. In this review, we address the technology of Raman fiber lasers, specifically focused on the most recent developments. We will also discuss several applications of Raman fiber lasers in laser pumping, frequency conversion, optical communications and biology.

High power, high efficiency, continuous-wave supercontinuum generation using standard telecom fibers

“…For high power near 1310nm, we have utilized a recently developed, Ytterbium fiber laser pumped, grating-free, cascaded Raman laser based on distributed feedback [14][15][16][17][18]. The pump wavelength (which is the emission wavelength of Yb laser) in the normal dispersion region undergoes a series of cascaded Raman shifts in the telecom fiber, to longer wavelengths beyond 1.3micron, thereby transferring the power to anomalous dispersion region.…”

“…In order to achieve efficient cascaded Raman conversion in a single pass architecture it is essential to provide a feedback in the forward direction which will induce preferential forward Raman scattering. This enhances the conversion efficiency and stability [14]. We have used a Raman conversion module based on distributed feedback technique [15,16] that can provide grating free, wavelength independent feedback [17,18].…”

Fiber Amplifiers and Fiber Lasers Based on Stimulated Raman Scattering: A Review

“…In addition, it is worth highlighting the unique property of Raman laser, i.e., they can be operated at several wavelengths simultaneously. Higher-order Stokes wavelengths can be generated inside the active medium at high pump powers and they can be properly dispersed spatially in association with separate mirrors for each Stokes beam [62].…”

Wide-Span Multi-Wavelength High-Power Diode-Laser Pumping of Fiber Raman Laser

“…F IBER Raman lasers (FRLs) are acclaimed for their potential as wavelength-agile and efficient brightness enhancers when pumped by multimode pump sources such as diode lasers [1], [2]. The possibility to use well-established silicabased fibers as the gain medium adds to their attraction [3]. However, stimulated Raman scattering (SRS) is a weak nonlinear process compared to ion-based absorption and emission processes and therefore requires much brighter pump sources and longer fibers than what are typically used for rare-earthdoped fiber lasers.…”