1,720,970 research outputs found
Transient effects in burst-mode operation of pulsed barium vapor lasers
No full textAn externally heated barium laser has been operated in burst mode in order to investigate the approach of the medium to steady-state operation in a continuously pulsed self-heated mode. Studies of the temporal evolution of discharge-current and cathode-voltage waveforms and laser output throughout a burst of pulses reveal short-term (first few pulses) and long-term (tens of pulses) transient effects. The former are attributed to changing prepulse conditions early in the burst, and the latter to the build up of radial thermal gradients in the laser medium due to gas heating. Simple models enabling the calculation of time-averaged radial gas temperature profiles in the steady-state limit and temporal evolution of spatially averaged gas temperatures are presented to elucidate the effects of gas heating
Ytterbium fiber lasers: versatile sources for the 1-1.2-µm region
No full textYtterbium doped silica fibers can offer very versatile laser sources in the 1-1.2-µm region with a wide range of possible pumps and operating wavelengths. In particular operation is possible from 980 nm to at least 1.18 µm. This range covers operation at 1.017 µm, suitable for up-conversion or for the 1.3 µm amplifier in Pr3+ ZBLAN fiber, and operation at 1.12 µm suitable for up-conversion in Tm3+ ZBLAN. We report here experimental results and modeling aimed at optimizing performance of Yb3+ fiber lasers for these various applications
A Pr<sup>3+</sup>-doped ZBLAN fibre upconversion laser pumped by an Yb<sup>3+</sup>-doped silica fibre laser
No full textAn Yb3+-doped silica fibre laser pumped at 840nm has been used to provide the two pump wavelengths, 840nm and 1020nm, required for pumping a Pr3+-doped ZBLAN fibre upconversion laser. The performance of the upconversion laser at 491, 520 and 635nm is presented, with measurements of fibre loss at 635nm and 520nm which indicate that fibre losses are an important factor limiting the performance of the upconversion laser
An Yb-doped silica cladding-pumped fibre laser pumped at 974nm
No full textAn Yb-doped silica fibre has been developed for cladding pumping at 374nm. Cladding-pumped laser action has been demonstrated with slope efficiencies up to 80%
A laser diode pumped optical amplifier in the first telecommunications window
No full textThulium doped fluorozirconate fibre has been shown to operate as an efficient amplifier over the wavelength range 800nm to 815nm in the first telecommunications window. Using a Ti:Sapphire laser at 780nm as pump source we have shown 23dB of gain at 805nm with 60mW of launched pump power
Ytterbium-doped silica fibre lasers: versatile sources for the 1-1.2µm region
No full textYtterbium-doped silica fibers exhibit very broad absorption and emission bands, from ~800 nm to ~1064 nm for absorption and ~970 nm to ~1200 nm for emission. The simplicity of the level structure provides freedom from unwanted processes such as excited state absorption, multiphonon nonradiative decay, and concentration quenching. These fiber lasers therefore offer a very efficient and convenient means of wavelength conversion from a wide variety of pump lasers, including AlGaAs and InGaAs diodes and Nd:YAG lasers. Efficient operation with narrow linewidth at any wavelength in the emission range can be conveniently achieved using fiber gratings. A wide range of application for these sources can he anticipated. In this paper, the capabilities of this versatile source are reviewed. Analytical procedures and numerical data are presented to enable design choices to be made for the wide range of operating conditions
Improved laser performance of Tm<sup>3+</sup> and Pr<sup>3+</sup>-doped ZBLAN fibres
No full textIn this paper we present the performance of Tm3+ and Pr3+-doped ZBLAN fibre lasers at blue, green, and red wavelengths, both pumped efficiently with the output of Yb3+-doped silica fibre lasers
Single frequency lasers and efficient cladding-pumped lasers using Yb<sup>3+</sup>-doped silica fibre
No full textYb3+-doped germanosilicate fibre has been demonstrated to be a versatile host for laser action at wavelengths from 1 to 1.2µm. It can be pumped at wavelengths from 800-1064nm, and the emission band extends from 970-1200 nm, including wavelengths of interest for specific applications, e.g., 1020nm for pumping of 1.3µm Pr3+-doped fibre amplifiers, 1140nm for pumping of Tm3+-doped fluoride fibre upconversion lasers, and 1083nm for optical pumping of 3He
Operation of cladding-pumped Yb<sup>3+</sup>-doped silica fibre lasers in 1µm region
No full textConversion efficiencies of up to 80% with respect to incident pump power are reported for 975nm pump light using cladding-pumped Yb-doped silica fibre lasers
Recent advances in Yb<sup>3+</sup>-doped silica fibre lasers
No full textRecent advances in the operation of Yb3+-doped silica fibre lasers will be presented. including very efficient (up to 80%) cladding-pumped operation at 1020, 1040 and 1140nm, and the development of single-frequency sources for spectroscopic applications
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