Preparation of Yb3+-doped silica-based glass for high power laser applications (original) (raw)
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La2O3-Al2O3-SiO2 Glasses for High-Power, Yb3+-Doped, 980-nm Fiber Lasers
Journal of the American Ceramic Society, 2004
Single-mode semiconductor pumps have failed to keep pace with the increasing power requirements of Er-doped fiber amplifiers (EDFAs), so there is a need for high-powered 980-nm sources. Yb 3؉ -doped tapered fiber lasers can provide high-power output by conversion of a low-brightness, highpowered, 920-nm, multimode broad stripe laser diode to a high-brightness, 980-nm, single-mode output. The tapered fiber laser requires a fiber with high numerical aperture (NA) (>0.4), a rectangular core, and good Yb 3؉ spectroscopy for efficient operation. CVD-based fiber fabrication methods are incapable of delivering fibers with an NA > ϳ0.3 or with good efficiency at 980 nm so a new method of high-NA fiber fabrication was developed. The core glass composition is critical for maintaining a high-NA fiber with good power extraction while avoiding phase separation, loss, and clustering. The SiO 2 level controlled the NA and interdiffusion between core and clad, while the Al 2 O 3 /La 2 O 3 ratio controlled phase separation. A La 2 O 3 -Al 2 O 3 -SiO 2 glass was developed that is compatible with a pure SiO 2 cladding glass and has a laser slope efficiency of 70% at 980 nm. The optimized fiber composition yielded 450 mW of 980-nm power in a singlemode fiber. † ␣ is the refractive index profile parameter.
A highly efficient Yb-doped silica laser fiber prepared by gas phase doping technology
Laser Physics, 2014
In this paper we report on an alternative technique for the preparation of ytterbium (Yb)-doped silica fibers and their characteristics compared to the conventional modified chemical vapor deposition (MCVD) process in combination with solution doping and powder sinter technology (REPUSIL). In the case of the technique applied here, the active core diameter in the preform can be significantly increased via the deposition of Yb and the most important codopant, aluminum (Al), in the gas phase through the high-temperature evaporation of the Yb chelate compound and Al chloride in the MCVD process. The prepared preform shows a homogenous distribution of the refractive index and dopant concentration. The background loss of the drawn fiber was measured to be 25 dB km −1 at 1200 nm. Efficient lasing up to 200 W, showing a slope efficiency of about 80%, was demonstrated, which is comparable to fibers made via MCVD/solution doping and the REPUSIL technique.
Yb3+ doped single-mode silica fibre laser system for high peak power applications
Photonics Letters of Poland, 2020
We present ytterbium doped silica single-mode fibre components for high power and high energy laser applications. We developed in-house the fibre laser with high efficiency of 65% according to the launched power, the threshold of 1.16W and the fibre length of 20 m. We also elaborated the fibre with 20 µm in diameter core suitable for amplifying the beam generated in oscillator. We implemented made in-house endcaps to prove the utility of the fibre towards high peak power applications. Full Text: PDF ReferencesStrategies Unlimited, The Worldwide Market for Lasers: Market Review and Forecast, 2020 DirectLink J. Zhu, P. Zhou, Y. Ma, X. Xu, and Z. Liu, "Power scaling analysis of tandem-pumped Yb-doped fiber lasers and amplifiers", Opt. Express 19, 18645 (2011) CrossRef IPG Photonics, Product information, accessed: October, 2020. DirectLink J.W. Dawson, M. J. Messerly, R. J. Beach, M. Y. Shverdin, E. A. Stappaerts, A. K. Sridharan, P. H. Pax, J. E. Heebner, C. W. Siders, and C....
Fabrication and properties of Yb-doped silica glass films for laser waveguide application
Optical Materials, 2006
This paper describes the fabrication of Yb 3+-doped silica glass films prepared by RF magnetron sputtering for laser applications. The deposition parameters and the subsequent thermal treatments were accurately adjusted to obtain layers with appropriate structural characteristics (flat surface, homogeneity) and optical properties (refractive index, absorption and fluorescence emission). The structural properties of the deposited films have been investigated by infra-red absorption spectroscopy and atomic force microscopy, while the layer composition was determined by an Energy Dispersive X-ray spectrometer. The optical properties of the films have been investigated by time resolved photoluminescence, providing relevant parameters such as the Yb 3+ fluorescence lifetime that governs the high pump energy storage and laser efficiency. The obtained values of the lifetime are scaling from 50 to 610 ls, and therefore are comparable to those usually reported for Yb 3+-doped silica glass fibers.
Ytterbium-doped metaphosphate laser glasses were prepared by the melt-quenching technique and their optical, thermo-mechanical and laser properties were characterized. Linear and non-linear refractive indices, laser-induced damage threshold, microhardness number and thermal expansion co-efficient have been evaluated for 1.0 mol% Yb2O3-doped glass. Low non-linear refractive index, high laser-induced damage threshold and low thermal-expansion coefficient have been noticed. Vickers hardness (4.07 GPa) for the present glass is found to be higher than that of Schott (APG-1; 3.09 GPa) glass and comparable with the Hoya (HAP-4; 4.70 GPa) glass. Higher magnitudes of absorption cross-sections (4.49–1.47 × 10–20 cm2), emission cross-sections (6.08–2.06 × 10–20 cm2) at 975 nm and (1.28–0.63 × 10–20 cm2) at 1.0 μm have been found along with an acceptable bandwidth (52–58 nm) when the Yb2O3 concentration varied from 0.01 to 1.0 mol%. All the studies reveal that the Yb3+ -doped metaphosphate laser glasses could be suitable as a gain media for high energy and high power laser applications at ∼1.0 μm region.
Optical properties of Yb3+ ions in fluorophosphate glasses for 1.0 lm solid-state infrared lasers
Yb 3?-doped fluorophosphate glasses were prepared by melt-quenching technique and characterized their spectroscopic properties to assess the laser performance parameters. The magnitude of absorption (emission) crosssections at 975 nm for all the studied Yb 3?-doped glasses is found to be in the range of 0.29-1.50 9 10-20 (0.59-1.99 9 10-20 cm 2) which is much higher than those of commercial Kigre QX/Yb: 1.06 9 10-20 (0.5 9 10-20 cm 2) laser glass. The luminescence lifetimes of 2 F 5/2 level decrease (1.15-0.45 ms) with increase in Yb 2 O 3 concentration (0.1-4.0 mol%). Effect of OHcontent on luminescence properties of Yb 3? ions has also been investigated. The effect of radiative trapping has been discussed by using McCumber (McC) and Fuchtbauer-Ladenburge (F-L) methods. The product of experimental lifetimes and emission cross-sections for 0.1 mol% Yb 2 O 3doped glass is found to be 2.28 9 10-20 cm 2 ms which indicates that the higher energy storage and extraction capability could be possible. The detailed spectroscopic results suggest that the studied glasses can be considered for high-power and ultrashort pulse laser applications.
Spectral characterization of Yb–doped silica layers for high power laser applications
Optical Materials, 2011
Thick silica layers, doped with rare-earth elements are required as active media for high power waveguide lasers and amplifiers. In this work, Yb/Al-codoped silica particles were deposited on pure silica wafers, followed by high temperature sintering and post-sinter laser annealing treatment. The optical properties of the layers were monitored at different stages of the process using transmission spectrometry in the near IR to UV range, micro-Raman spectroscopy, fluorescence spectrum, and decay measurements. Evolution of the Yb 3+ ion fluorescence and stabilization of the Si:O bonds as a result of the sintering process were observed. Measurements of 30 lm thick layers showed high Yb absorption of 500 dB/m at 980 nm. The fluorescence lifetime was close to 1 ms and the propagation loss was less than 20 dB/m at 633 nm, currently limited by the measurement system. The results show that a potential material for high power applications has been achieved.
Yb3+:Al3+:sol–gel silica glass fiber laser
Optical Materials, 2007
For the first time, an ytterbium-doped aluminum co-doped silica glass fiber laser has been produced by the sol-gel technique. The laser has a threshold of 79.7 mW launched power and a slope efficiency of 73%. The maximum output of 34.2 mW was limited by the available pump power. The emission is tunable from 1033 to 1108 nm. The losses of the fiber at a wavelength of 1100 nm are 31.2 ± 2.2 dB/km.
Optics Letters, 2015
We have fabricated and tested a composite fiber with an Yb 3-doped phosphate glass core and silica cladding. Oscillation with a slope efficiency of 74% was achieved using core pumping at 976 nm with fiber lengths of 48-90 mm in a simple laser configuration, where the cavity was formed by a high-reflectivity Bragg grating and the cleaved fiber end. The measured M 2 factors were as low as 1.05-1.22 even though the fiber was multimode at the lasing wavelength.
A highly efficient ytterbium-free erbium-doped silicate glass fiber has been developed for high-power fiber laser applications at an eye-safe wavelength near 1.55 μm. Our preliminary experiments show that high laser efficiency can be obtained from a relatively short length of the gain fiber when resonantly pumped at 1535 nm in both core-and cladding-pumping configurations. With a core-pumping configuration as high as 75%, optical-to-optical efficiency and 4 W output power were obtained at 1560 nm from a 1 m long gain fiber. When using a cladding-pumping configuration, approximately 13 W output power with 67.7% slope efficiency was demonstrated from a piece of 2 m long fiber. The lengths of silicate-based gain fiber are much shorter than their silica-based counterparts used in other experiments, which is significantly important for high-power narrow-band and/or pulsed laser applications.