33 research outputs found
Operation of ytterbium-doped silica fibre lasers at specific wavelengths using fibre gratings
Yb-doped fibre lasers have been previously reported as versatile, efficient laser sources in the 1 µspectral region. The very broad Stark splitting of Yb energy levels in silica results in wide pump (830 - 1064 nm) and emission (975 - 1160 nm) bands. The emission band includes a number of wavelengths of interest for specific uses; examples include 1020 nm, the optimum pump wavelength for the Pr:ZBLAN amplifier and upconversion laser, and 1128 nm. which has been utilised to pump a Tm:ZBLAN upconversion laser
All solid-state blue room-temperature thulium-doped upconversion fibre laser
Following the report by Grubb we describe an all solid state, single wavelength pumped, cw, room temperature, upconversion laser which has operated in the blue between 475nm and 483nm or in the near infrared at 778nm. We have pumped this device at both longer and shorter wavelengths than those reported by Grubb. The system uses Yb-doped silica fibre to convert the output from a diode pumped Nd:YLF laser to a wavelength in the range 1.05µm to 1.18µm. This is used to pump a Tm-doped ZBLAN fibre giving rise to an upconversion process which involves the sequential absorption of three pump photons to populate the 1G4 upper laser level as shown in Fig 1
Transient effects in burst-mode operation of pulsed barium vapor lasers
An 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
A Pr<sup>3+</sup>-doped ZBLAN fibre upconversion laser pumped by an Yb<sup>3+</sup>-doped silica fibre laser
An 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
Ytterbium fiber lasers: versatile sources for the 1-1.2-µm region
Ytterbium 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
Efficient upconversion laser action in Tm<sup>3+</sup> and Pr<sup>3+</sup>-doped ZBLAN fibres
Visible wavelength lasers are much sought after for many applications. In this paper we report that significant powers at blue (46 mw), green (5 mw) and red (30 mw) are now available from Tm3+ and Pr3+-doped ZBLAN fiber lasers using very convenient pumping schemes based on the Yb3+-doped silica fiber laser
An Yb-doped silica cladding-pumped fibre laser pumped at 974nm
An 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%
Ytterbium-doped silica fibre lasers: versatile sources for the 1-1.2µm region
Ytterbium-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