Abstract. In present-day single-rod/single-beam solar laser systems, the thermal lens effect is a serious issue that limits its ability for a scale-up to higher powers and improved beam quality. Aiming at resolving this shortcoming, the concept of a seven-rod/seven-beam solar pumping scheme is proposed. This scheme was composed of a first-stage heliostat-parabolic mirror system and a single large laser head. The large laser head consisted of seven fused silica compound parabolic concentrators, which transmitted and focused the concentrated solar radiation to each single-laser rod of small diameter, within a conical cavity, which enabled multiple passages of the pump rays. Consequently, each laser rod was pumped by only one-seventh of the total concentrated solar power, ensuring a significant reduction of the thermal induced effects in the laser rods. 13.3 W/m2 TEM00-mode solar laser collection efficiency was numerically achieved, representing an enhancement of 1.68 times over the experimental record from a single-rod prototype. 1.80 times improvement in solar-to-TEM00-mode laser power conversion efficiency was also registered in relation to the previous experimental record.

中文翻译：

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用于同时发射七束 TEM00 模式太阳能激光束的七杆泵浦概念

摘要。在当今的单杆/单光束太阳能激光系统中，热透镜效应是一个严重的问题，限制了其放大到更高功率和改进光束质量的能力。针对这一不足，提出了七杆/七光束太阳能抽水方案的概念。该方案由第一级定日镜抛物面镜系统和单个大型激光头组成。大型激光头由七个熔融石英复合抛物面聚光器组成，将聚集的太阳辐射传输并聚焦到锥形腔内的每个小直径激光棒上，从而使泵浦光线能够多次通过。因此，每个激光棒仅被总聚光太阳能的七分之一泵浦，确保显着减少激光棒中的热感应效应。在数值上实现了 13.3 W/m2 TEM00 模式太阳能激光收集效率，比单杆原型的实验记录提高了 1.68 倍。与之前的实验记录相比，太阳能到 TEM00 模式的激光功率转换效率也提高了 1.80 倍。