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Introduction to Laser Ranging, Profiling, and Scanning
Published in Jie Shan, Charles K. Toth, Topographic Laser Ranging and Scanning, 2018
Gordon Petrie, Charles K. Toth
The Nd:YAG laser has been adopted quite widely as the basis of the laser rangefinders used in airborne laser scanners. A less commonly used solid-state laser is that employing yttrium lithium fluoride (YLF) as the matrix material. Again this is doped using a small amount of Nd to form the Nd:YLF laser. This has been used for example in NASA’s RAster SCanning Airborne Laser (RASCAL) airborne laser scanner. Yet another material that has been used in NASA-built and NASA-developed airborne scanners is neodymium-doped yttrium vanadate (Nd:YVO4). Compared with the Nd:YAG laser, the so-called vanadate laser has the advantage that it allows very high pulse repetition rates; on the other hand, it does not allow as high a pulse energy with Q-switching as the Nd:YAG laser. The Terrapoint Airborne LiDAR Terrain Mapping System (ALTMS) airborne laser scanners, which were developed originally with the assistance of NASA, all utilized these vanadate lasers.
Introduction to Laser Ranging, Profiling, and Scanning
Published in Jie Shan, Charles K. Toth, Topographic Laser Ranging and Scanning, 2017
Gordon Petrie, Charles K. Toth
The Nd:YAG laser has been adopted quite widely as the basis of the laser rangefinders used in airborne laser scanners. A less commonly used solid-state laser is that employing yttrium lithium fluoride (YLF) as the matrix material. Again this is doped using a small amount of Nd to form the Nd:YLF laser. This is used for example in NASA's RASCAL airborne laser scanner. Yet another material that has been used in NASA-built and -developed airborne scanners is neodymium-doped yttrium vanadate (Nd:YVO4). Compared with the Nd:YAG laser, the so-called “vanadate” laser has the advantage that it allows very high pulse repetition rates; on the other hand, it does not allow as high a pulse energy with Q-switching as the Nd:YAG laser. The Terrapoint ALTMS airborne scanners, originally developed with the assistance of NASA, all utilize these “vanadate” lasers.
Materials for Solid-State Lasers
Published in Moriaki Wakaki, Optical Materials and Applications, 2017
Yttrium lithium fluoride (YLF) with Nd3+ ion offers a laser transition of 1053 nm, which matches the pumping of Nd-doped phosphate and fluorophosphate glasses. The chemical formula for YLF is LiYF4. YLF has a tetragonal crystal structure. Its material properties are summarized [5,6] in Table 4.4. This crystal has a natural birefringence that can eliminate its depolarization thermally. The maximum doping of Nd is empirically limited to 3 wt%.
Ensemble modelling technique for a micro-drilling process based on a two-stage bootstrap
Published in Engineering Optimization, 2019
Linhan Ouyang, Dequn Zhou, Chanseok Park, Jianxiong Chen, Yiliu Tu
The rest of the article is organized as follows. Section 2 shows a basic process assumption in RSM. Section 3 presents the proposed ensemble modelling technique based on a two-stage bootstrap method and then gives a new optimization strategy that simultaneously considers the optimality and the reliability of operating conditions. In Section 4, a neodymium-doped yttrium lithium fluoride (Nd:YLF) laser beam micro-drilling process is analysed to illustrate the efficiency of the proposed modelling technique. Some concluding remarks and directions for future research are given in Section 5.