With their method, the length of the fibre can be controlled, and the cross section of the perovskite fibre core can be varied. They gradually changed the heating position, line contact and temperature during the process to ensure continuous growth in the length while preventing random growth in the width. Scientists have therefore been seeking to make single-crystal perovskite optical fibres that can bring this high efficiency to fibre optics.ĭr Su, Reader in Photonics at Queen Mary University of London, said: 'Single-crystal perovskite fibres could be integrated into current fibre-optical networks, to substitute key components in this system - for example in more efficient lasing and energy conversions, improving the speed and quality of our broadband networks.'ĭr Su's team were able to grow and precisely control the length and diameter of single-crystal organometallic perovskite fibres in liquid solution (which is very cheap to run) by using a new temperature growth method. The optical fibres have a core width as low as 50 μm (the width of a human hair) and are very flexible - they can be bent to a radius of 3.5mmĬompared to their polycrystal counterparts, single-crystal organometallic perovskites are more stable, more efficient, more durable and have fewer defects. The perovskite optical fibre made by Dr Su's team consists of just one piece of a perovskite crystal. At present, most optical fibres are made of glass. These tiny optical fibres transmit the majority of our internet data. 192, 1300–1307 (2017).Optical fibres are tiny wires as thin as a human hair, in which light travels at a superfast speed - 100 times faster than electrons in cables. Gerasimenko, “Fe:ZnMnSe laser active material at 78–300 K: Spectroscopic properties and laser generation at 4.2–5.0 μm,” J. Zhavoronkov, “Luminescent and lasing characteristics of polycrystalline Cr:Fe:ZnSe exited at 2.09 and 2.94 μm wavelengths,” Laser Phys. Hang, “Preparation, spectroscopic characterization and energy transfer investigation of iron-chromium diffusion co-doped ZnSe for mid-IR laser applications,” Opt. Mirov, “Mid-IR photoluminescence of Fe 2+ and Cr 2+ ions in ZnSe crystal under excitation in charge transfer bands,” Opt. Mirov, “Mid-IR laser oscillation via energy transfer in the Co:Fe:ZnS/Se co-doped crystals,” Proc. Fedorov, and S. B. Mirov, “Mid-lasing of iron–cobalt co-doped ZnS(Se) crystals via Co–Fe energy transfer,” J. Shapkin, and V. V. Shchurov, “Fe 2+:ZnSe laser pumped by a nonchain electric-discharge HF laser at room temperature,” Quantum Electron. Badikov, “Bulk Fe:ZnSe laser gain-switched by the Q-switched Er:YAG laser,” Proc. Vasilyev, “Progress in mid-IR lasers based on Cr and Fe-doped II–VI chalcogenides,” IEEE J. Gapontsev, “Progress in Cr and Fe doped ZnS/Se mid-IR CW and femtosecond lasers,” Proc. Frolov, “Efficient IR Fe:ZnSe laser continuously tunable in the spectral range from 3.77 to 4.40 μm,” Quantum Electron.
Voronov, “3.77–5.05-μm tunable solid-state lasers based on Fe 2+-doped ZnSe crystals operating at low and room temperatures,” IEEE J. Payne, “4.0–4.5-μm lasing of Fe:ZnSe below 180 K, a new mid-infrared laser material,” Opt. The Fe 2+ ions output pulses were quite stable in amplitude and temporal domain in both excitation modes with beam profile close to the fundamental transversal mode.
The Fe 2+ ions oscillation wavelength was observed to shift with temperature increase from ~4.4 μm at 78 K to ~4.5 μm at 150 K.
Laser generation at 2.3 μm was observed up to 340 K while Fe 2+ ions oscillations stopped for temperatures above ~150 K. In the Cr 2+ → Fe 2+ energy transfer mode, the maximum output energy was 20 μJ at 4.4 μm. The output energy for Cr 2+ ions lasing at 2.3 μm was up to 900 μJ while Fe 2+ ions lasing at 4.4 μm reached up to 60 μJ in the intracavity pumping mode. intracavity pumping of Fe 2+ ions by Cr 2+ ions as well as excitation through the Cr 2+ → Fe 2+ ions energy transfer mechanism, were demonstrated. Under pumping by a Q-switched Er:YLF laser at 1.73 μm, the oscillations of Cr 2+ ions at 2.3 μm as well as Fe 2+ ions at 4.4 μm were realized. Novel Cr 2+ and Fe 2+ co-doped Zn 1– xMn xSe ( x = 0.3) crystal with Cr 2+ to Fe 2+ ions concentration ratio of about 1 : 2 (both doping ions concentration were at the ~10 18 cm –3 level) with a good optical quality was synthesized.
0 kommentar(er)
