1,720,971 research outputs found
A 11.5 W Yb:YAG planar waveguide fabricated via pulsed laser deposition
No full textDataset for the figures in Grant-Jacob, James A, Beecher, Stephen J, Parsonage, Tina L, Hua, Ping, Mackenzie, Jacob I, Shepherd, David P and Eason, Robert W (2015) An 11.5 W Yb:YAG planar waveguide laser fabricated via pulsed laser deposition. Optical Materials Express
Data collection method: Optical spectrum analyzer (Ando AQ6317).</span
Pulsed laser deposition of doped sesquioxide films for planar waveguide lasers
No full textThe sesquioxides Y2O3, Lu2O3 and Sc2O3 have been identified as promising laser host materials due to their excellent thermo-mechanical properties and ability to be doped with rare-earth ions. However, crystals of these materials are problematic to grow due to their high melting points of ~2500°C, which means standard methods of crystal growth from a melt need to be modified to deal with such high temperatures and become more expensive. Pulsed laser deposition (PLD) has the capability to grow these materials, without requiring a melt of material to grow from. Sintered ceramic targets of the sesquioxides, often doped with rare-earth ions, are ablated with a UV laser pulse and material is ejected. This plume of material travels through a vacuum chamber to a carefully chosen substrate where material is deposited and forms a crystalline film.Planar waveguide lasers are structures of interest due to their low lasing thresholds in comparison to bulk material, owing to the greater overlap of the pump and laser modes, and their large aspect ratio that allows efficient heat removal from the laser crystal. This, combined with the high thermal conductivity of the sesquioxides, should allow for power scaling of these waveguide lasers with minimal thermal affects. The laser results in this thesis are for progressively higher powers, and no detrimental heating affects are witnessed.This thesis reports on the growth of single and multilayer sesquioxide waveguides grown by PLD, including growth optimisation, sample analysis and laser experiments. The first sample of this project to be successfully lased was a single layer Tm:Y2O3 waveguide on a YAG substrate, which produced a maximum output power of 35 mW with 9% slope efficiency at a wavelength of 1.95 µm, and, to the best of our knowledge, was the first Tm:Y2O3 planar waveguide laser. Next, Yb:Y2O3 was the material of choice and a multilayer sample was fabricated, where the Yb:Y2O3 core was sandwiched between two undoped Y2O3 layers, again on a YAG substrate. Laser experiments with this waveguide gave a maximum output power of 1.2 W at 1030 nm, with a slope efficiency of 20%. The highest laser output power of any of the doped sesquioxide waveguides in this project is 8.5 W, achieved using a Yb:Lu2O3 sample
Thulium-doped yttria planar waveguide laser grown by pulsed laser deposition
No full textLasers operating in the 2 micron wavelength region are of particular interest for various applications in remote sensing/LIDAR, materials processing, and medical treatments. Thulium-doped media have several attractive features for generating light in this wavelength band, including a broad emission bandwidth, long-lived metastable states, absorption bands matched to high-power 0.8 mm diode-pump sources coupled with the potential for high quantum-efficiency due to a 2-for-1 cross-relaxation process. The sesquioxide crystal family is of considerable interest as a potential host due to their excellent thermo-optic characteristics and spectroscopic properties. A key challenge for this host material is its high-temperature growth requirements (some in excess of 2500 K for bulk crystals); as such there has been limited success in fabricating these crystals commercially. Here we report the first growth and lasing results (to the best of our knowledge) of a crystalline Tm:Y2O3 waveguide, fabricated via pulsed laser deposition (PLD)
Dataset for Yb:YAG planar waveguide lasers grown by pulsed laser deposition: 70% slope efficiencies at 16 W of output power
No full textData for the figures in the paper "Beecher, S.J., Grant-Jacob, J.A., Parsonage, T.L., Hua, P., Mackenzie, J.I., Shepherd, D.P. and Eason, R.W. (2016) Yb:YAG planar waveguide lasers grown by pulsed laser deposition: 70% slope efficiencies at 16 W of output power. In, Solid State Lasers XXV: Technology and Devices, San Francisco, US, 13 - 18 Feb 2016. (doi:10.1117/12.2220388)."</span
Dataset for Engineering of thin crystal layers grown by pulsed laser deposition
No full textData associated with SPIE Photonics Europe Proceedings paper "Engineering of thin crystal layers grown by pulsed laser deposition".</span
Laser operation of a Tm:Y<sub>2</sub>O<sub>3</sub> planar waveguide
No full textWe demonstrate the first Tm-doped yttria planar waveguide laser to our knowledge, grown by pulsed laser deposition. A maximum output power of 35 mW at 1.95 µm with 9% slope efficiency was achieved from a 12 µm-thick film grown on a Y3Al5O12 substrate
Pulsed laser deposited crystalline optical waveguides for thin-film lasing devices
No full textWe have used the technique of pulsed laser deposition (PLD) to grow doped crystalline films of garnets (YAG) and sesquioxdes (Y2O3, Sc2O3, and Lu2O3) for application as optically-pumped waveguide lasers. For the sesquioxides in particular, PLD offers a real advantage in terms of the ~1100K growth temperature required to grow crystalline thin films in comparison to ~2750K required to grow bulk crystals. We can grow these materials at the rate of ~4 µm per hour, on cheap and readily available single-crystal YAG substrates, which allows rapid production of waveguide samples of the ~10-20 µm thickness required for efficient pumping via high-power diode lasers.The sesquioxide films grow preferentially in the (222) crystal orientation, and although there is an excellent lattice match to the (100) oriented YAG substrates, the four-fold symmetry associated with the (222) growth direction can lead to the presence of domain boundary problems that contribute to an undesirable optical loss within these waveguide hosts. In contrast the garnet hosts experience ideal epitaxial growth (i.e. YAG films grown on YAG substrates) where the presence of the dopant lasing ion produces the necessary refractive index requirement for waveguide operation.We will discuss the range of lasing results we have achieved so far, which includes c.w. lasing within single waveguide films, capped layers and multilayer structures where the doped lasing layer has been grown within a 3-layer sandwich structure [1,2]. We will also describe results where a single layer of graphene has been deposited on either the output coupler mirror, or on the top surface of the guide, to produce pulsed laser output in q-switched mode [3-4]. Since these lasing waveguides are optically pumped by diode lasers, it is important to design these guiding structures to ensure efficient operation in terms of low threshold and high slope efficiency. Details will be given on optimum waveguide design as well as our strategy on further reduction of optical propagation losses
Diode-end-pumped 1.2W Yb:Y<sub>2</sub>O<sub>3</sub> planar waveguide laser
No full textFabrication, characterization and laser performance of a Watt level ytterbium-doped yttria waveguide laser is presented. The waveguide was grown onto a YAG substrate by pulsed laser deposition and features a 6 µm thick ytterbium-doped yttria layer sandwiched between two 3 µm undoped yttria layers. The laser deposited film was characterized by X-ray diffraction, showing a high degree of crystallinity and analyzed spectroscopically, showing performance indistinguishable from previously reported bulk material. When pumped with 8.5 W from a broad area diode laser the waveguide laser produces 1.2 W of output at 1030 nm
Pulse laser deposition growth of functional garnet crystal films
No full textInvited Talk at Goddard Space Flight Center (NASA) on 4th November 2016
Q-switched operation of a pulsed-laser-deposited Yb:Y<sub>2</sub>O<sub>3</sub> waveguide using graphene as a saturable absorber
No full textThe first, to the best of our knowledge, Q-switched operation of a pulsed-laser-deposited waveguide laser is presented. A clad Yb:Y2O3 waveguide was Q-switched using an output coupling mirror coated with a single layer of graphene deposited by atmospheric pressure chemical vapor deposition. During continuous-wave operation, a maximum power of 83 mW at a slope efficiency of 25% was obtained. During Q-switched operation, pulses as short as 98 ns were obtained at a repetition rate of 1.04 MHz and a central wavelength of 1030.8 nm
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