太陽光から直接レーザー媒質を励起してレーザーを出す
太陽光励起レーザーを実用化しようとした元東工大矢口教授は
その野望を果たすことができなかった。
彼ほどの情熱を持った後継者は現れなかった。
ところが中国には諦めていない研究者がいてセリウムをドープして
改良をしようとする研究者も出てきたが
あと一歩というところだ。
その現状を知ろうと思ったら
レビュー論文を読むのがいい。
これだ。
deepL翻訳は以前は使いやすかったが、今ではちょっと。
Google翻訳はなんとか使えるかもしれない。
A review on design modalities of solar-pumped solid-state laser
Abstract
The rapid exhaustion of conventional energy sources and global environmental concerns are opening new opportunities to utilize sustainable and renewable energy. Amid the various renewable sources, solar energy is a promising, inexhaustible, and abundant form of freely available energy. The solar-driven laser system is one of the most acceptable technologies to harness solar power. Solar-powered laser converts the broadband solar radiation directly into the monochromatic, collimated, and coherent laser beam. The emitted laser beam may be widely used in space and terrestrial applications, including free-space optical communication, renewable energy cycle, asteroid deflection, space debris removal, material processing, nano-material production, and electric vehicles. The paper starts with a discussion of solar-powered lasers with distinct gain mediums such as liquid, gas, and solid. This paper illustrates details about the solar-powered solid-state lasers, which have the advantage of inherent high energy density and compactness, relatively low pumping threshold, and potential for efficient solar to laser power conversion. A comprehensive review of solid-state solar laser's construction, working principle, energy conversion process, and beam shaping are also presented. The state‐of‐the‐art procedures have been summarized for laser collection efficiency and laser output power. The power density of solar radiations received on the earth's surface is low and insufficient for lasing action. Hence, the solar concentrators are described in detail to enhance the energy density. Furthermore, the different Nd: YAG laser rods and pumping schemes are explained to reduce the thermal lens effect. Finally, the review is concluded with a conclusion and perspectives.