Highly nonlinear yttrium-aluminosilicate optical fiber with a high intrinsic stimulated Brillouin scattering threshold

Abstract

Highly nonlinear (high-NA small-mode-area) optical fibers also possessing intrinsically high stimulated Brillouin scattering (SBS) threshold are described. More specifically, silica clad, yttrium-aluminosilicate core fibers are shown to exhibit an intrinsically low Brillouin gain coefficient between 0.125 and 0.139 × 10 -11 m/W, and a Brillouin gain linewidth of up to 500 MHz. Losses on the order of 0.7 dB/m were measured, resulting from impurities in the precursor materials. Nonlinear refractive index values are determined to be similar to that of silica, but significant measurement uncertainty is attributed to the need to estimate dispersion curves since their direct measurement could not be made. The interest for highly nonlinear optical fibers with a low intrinsic Brillouin gain coefficient is expected to continue, especially with the growing developments of narrow-linewidth high energy laser systems.

The preparation of Yttrium Aluminosilicate (YAS) Glass Fiber with heavy doping of Tm3+ from Polycrystalline YAG ceramics

“…In recent years, many efforts were paid to the preparation of optical fibers with YAS glass core for optical applications and laser output have already been realized with different kinds of doped ions (Nd 3+ , Yb 3+ , Er 3+ ) . The relatively high content of Al and Y of the fiber core is beneficial to suppress the stimulated Brillouin scattering (SBS) and achieve higher doping concentration of rare earth ions than in the silica fiber . With regard to the preparation of such YAS optical fiber, YAG crystal or ceramic was used and inserted into a silica tube to form a preform and then to prepare optical fiber.…”

Glass: The carrier of light—Part II—A brief look into the future of optical fiber

“…The approach also is applicable to a wide range of properties, even enabling wholly new applications; see Table 1. [83][84][85][86][87][88][89][90] So, to the question "how low can one go with more being less," the answer, certainly with respect to parasitic optical nonlinearities, is "very low, occasionally zero, and with surprisingly simple glasses and processes. "…”

“…An important difference with this “material intermediate value theorem,” relative to the previously mentioned linear doping approach, is that the effective property value (nonlinearity in this case) reduces precipitously when the “zero composition” is approached, even for simple bi‐ or tri‐component silica‐based glasses, for example, Figure 1. The approach also is applicable to a wide range of properties, even enabling wholly new applications; see Table 1 83‐90 …”

A Brief Review of Specialty Optical Fibers for Brillouin-Scattering-Based Distributed Sensors

“…Making this approximation can then simplify the mathematical analysis to some extent. In the case of acoustically anti-guiding fibers, the longitudinal wave also becomes leaky (again assuming an infinite cladding) and can contribute waveguide loss comparable to, or even much larger than [47] that of the material [44]. As discussed below, this acts to broaden the Brillouin gain spectrum (BGS) and reduce the peak gain coefficient; potentially undesirable characteristics for some distributed sensor applications.…”