810 research outputs found
Circular output from a high power Nd:YLF slab laser
No full textNeodymium-doped Yttrium Lithium Fluoride (YLF) lasers have traditionally been power-limited by the relatively low tensile strength of the crystal. When power-scaling solid-state lasers, the choice of the gain media geometry, the doping level, and the pumping scheme is dictated by minimizing the impact of thermally induced stress. To date the slab architecture has been the most successful for scaling the average-power of Nd:YLF lasers due to its favorable thermal management. However, for efficient high-radiance laser action it is also necessary to have a good overlap between the cavity mode and the planar gain volume. We present the performance characteristics for an end-pumped slab-laser utilizing a stable low-loss resonator configuration that transforms a circular cavity mode at the output coupler into a very high aspect ratio elliptical beam in the slab gain element to match the pumped volume. The optical arrangement for transforming the beam shape is also suitable for a double-pass slab amplifier configuration. A polarized CW output power of 50W, on the weaker Nd:YLF 1053nm transition was obtained with a single slab gain element and 110W of incident pump power from three spatially multiplexed diode bars. Laser threshold was around 7W and the slope efficiency, with respect to incident power, 46%
High-power fiber sources: recent advances and future prospects
No full textStrategies for scaling output power and brightness from rare-earth doped fiber lasers and amplifiers will be reviewed and the prospects for further improvement in performance will be considered
High power fibre lasers
No full textRecent progress in the development of high power fibre lasers will be reviewed, and the prospects for scaling output powers to well beyond the hundred watt level, whilst maintaining diffraction-limited beam quality will be discussed
Power-scaling concepts for solid-state lasers: crystal versus fiber
No full textScaling of laser power and brightness to meet the needs of ever-demanding applications is an activity which continues to preoccupy many within the laser community. In this tutorial, I will review recent progress in the development of power scaling strategies for crystal and fiber lasers, and will discuss their relative merits. In addition, I will also describe some alternative approaches for power scaling which combine the advantages of fiber and bulk lasers in the form of a hybrid laser
High power fiber lasers and amplifiers
No full textRecent advances in cladding-pumped fiber lasers and amplifiers have been dramatic, leading to unprecedented levels of performance in terms of output power, efficiency, beam quality and wavelength coverage. These achievements have attracted growing interest within the community and have fueled thoughts that fiber-based sources may one day replace conventional “bulk” solid-state lasers in many application areas. The main attractions of cladding-pumped fiber sources are derived directly from their geometry, which simultaneously allows very efficient generation of coherent light and almost complete immunity from the effects of heat generation, which are so detrimental to the performance of other types of lasers. This course aims to provide an introduction to high power fiber lasers and amplifiers, starting from the basic principles of operation and ending with examples of current state-of-the-art devices and some thoughts on future prospects. The course will cover a range of topics, including basic fiber laser and amplifier theory, spectroscopy of the relevant rare earth ions for high power devices, a discussion of the factors influencing laser and amplifier performance, fiber design and fabrication, pump sources and pump launching schemes, fiber resonator design, master-oscillator and power-amplifier configurations, linewidth control and wavelength selection, transverse mode selection, nonlinear loss processes (SBS and SRS) and their impact on performance, and heat generation and its impact on power scalability. The course will also give an overview of techniques (e.g. coherent and spectral beam combining) for further scaling of output power and provide an introduction to hybrid fiber-bulk laser schemes for scaling pulse energy
High power visible solid-state lasers
No full textRecent progress in power-scaling of diode-pumped visible solid-state sources using intracavity-frequency-doubling and single-pass (extra-cavity) nonlinear frequency conversion in periodically-poled lithium niobate will be discussed
Fibre-bulk hybrid lasers
No full textCladding-pumped fiber lasers are becoming increasingly attractive for high power generation due to their high efficiency and immunity from thermal effects. However, due their small core size and long device length, pulse energies are rather limited. In contrast, conventional ‘bulk’ solid-state lasers offer the prospect of much higher pulse energies, but suffer from detrimental thermal effects which can degrade beam quality and efficiency. An alternative strategy for scaling output power and pulse energy, which is attracting growing interest, is to use a hybrid laser scheme. In this approach, the fiber laser is used as a high-brightness source for in-band pumping of a bulk solid-state laser. One of the main attractions of the fiber-bulk hybrid laser scheme is that most of the heat generated via quantum defect heating is deposited in the fiber, and thermal effects in the bulk laser are dramatically reduced leading to the prospect of much improved efficiency, beam quality, higher average output power and higher pulse energy. This approach has already been successfully applied to a number of different solid-state lasers operating in the eyesafe wavelength regimes around 1.6µm and 2µm. In this presentation, we describe recent progress in the development of high-power fiber pump sources for hybrid lasers, and we will report on recent developments in power scaling of hybrid lasers in cw and in pulsed modes of operation
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