Development of Hollow Light Guide for Ultra-Violet Laser Power Transmission

中空光导板（以下简称中空光导板）的结构由两个反射金属板通过塑料垫片平行布置，并覆盖热收缩管组成。必须使用对激光具有高反射率的金属作为板材。我们选择铝作为反射板，因为它的反射率最高。由于铝反射镜的抛光精度难以提高，提出了一种镀铝的磷青铜板。反射器的制造工艺分为三个工序；抛光，清洗和铝涂层。在抛光过程中，使用专用的抛光机对磷青铜板进行抛光。在镀铝过程中，测试了磷青铜板的温度与反射率、铝的附着力的关系。获得了具有高反射率和较强附着力的最佳涂层条件。对传统铝质反射器与镀铝磷青铜反射器的反射率、激光损伤阈值和弯曲试验进行了对比研究。镀铝磷青铜板各项性能指标均明显优于铝板。使用上述反射器，KrF激光器的透过率为77%/m。输出能量达到110mJ/脉冲。由于ArF激光被空气高度吸收，因此ArF激光的透射率低于KrF激光。氦气对ArF激光的吸收最弱。对于氦气填充的HLG， ArF激光的透过率和输出能量分别达到72%/m和50mJ/脉冲。这些值不能达到本研究的目的，但这些结果给了我们成功的前景。在此基础上，设计了一种适用于医疗领域的准分子激光手术刀。在试验的基础上设计制造了激光器与高能效比的耦合部件和激光发射部件。少

The structure of the hollow light guide (hereafter refered to as the HLG) consists of two the reflective metal plates arranged in parallel through a plastic spacer and covered by a heat contraction tube. A metal with high reflectance to the laser light had to be utilized as plate material. We chose aluminum as a reflective plate because of the highest reflectance. Since it was difficult to raise the polishing accuracy of the aluminum reflector, a phosphor-bronze plate with aluminum coating was proposed for use. The manufacturing process of the reflector is divided into three processes ; the polishing, the washing and the aluminum coating. In the polishing process, a special polishing machine was made to polish the phosphor-bronze plate. In the aluminum coationg process, the relation between the temperature of the phosphor-bronze plate and the reflectance, and the adhesion of the aluminum were tested. The optimum coating conditions were obtained for the high reflectance and the tight ad … More hesion. A comparative study of the reflectance, the laser damage threshold, and the bend test was examined for the conventional aluminum reflector with those of the aluminum coating phosphor-bronze reflector. The aluminum coating phosphor-bronze plate was much superior in every test to the aluminum plate. The transmittance of the KrF laser was 77%/m using the above reflector. The delivery energy reached 110mJ/pulse. Since the ArF laser is highly absorbed into air, the transmittance of the ArF laser was lower than that of the KrF laser. Helium gas displayd the weakest absorption of the ArF laser. The transmittance and the delivery energy of the ArF laser reached 72%/m and 50mJ/pulse for helium gas-filled HLG,respectively. These values could not reached the goal of this study, but these results gave the prospect of our success. Based on the above results, an excimer laser scalpel applicable in the medical field using this HLG was designed. The coupling component of the laser and the HLG, the laser emission part were designed and manufactured on a trial basis. Less