Bor Z, Hopp B, Rácz B, Szabó G, Ratkay I, Süveges I, Füst A, Mohay J
Department of Optics and Quantum Electronics, JATE University, Szeged, Hungary.
Refract Corneal Surg. 1993 Mar-Apr;9(2 Suppl):S111-5.
Excimer lasers are now used for corneal surgery; however, the physical processes occurring during photoablation of the cornea are incompletely understood. High speed laser-based photographic arrangement was constructed. The temporal resolution was better than 1 ns. The setup could work as a Schlieren arrangement, which is sensitive to the refractive index change caused by the shock wave propagating in the air above the eye. With minor changes the setup was converted into a shadowgraph, which could detect the ablation plume and the waves propagating on the surface of the eye. Due to the impact of the excimer laser pulse onto the surface of the cornea, a shock wave was generated in the air. The shadowgraph clearly showed the ejection of the ablated cornea. The ejection velocity of the plume was found to be over 600 m/s. It was shown for the first time that the recoil forces of the plume are generating a wave on the surface of the eye. The laser-based high speed photographic arrangement is a powerful arrangement in the study of physical effects occurring during photoablation of the cornea.
准分子激光现在用于角膜手术；然而，角膜光消融过程中发生的物理过程尚未完全被理解。构建了基于高速激光的摄影装置。时间分辨率优于1纳秒。该装置可以作为纹影装置工作，它对由在眼睛上方空气中传播的冲击波引起的折射率变化敏感。只需稍作改动，该装置就可以转换为阴影图，能够检测消融羽流和在眼睛表面传播的波。由于准分子激光脉冲对角膜表面的冲击，在空气中产生了冲击波。阴影图清楚地显示了被消融角膜的喷射。发现羽流的喷射速度超过600米/秒。首次表明羽流的反冲力在眼睛表面产生了一个波。基于激光的高速摄影装置是研究角膜光消融过程中发生的物理效应的有力装置。
