Trokel等(1983)首先使用了在远紫外线区(193nm)发出辐射的准分子(excimer)激光器。这种辐射的穿透力约为1μm,只能产生很浅的约300nm左右的热损伤区。准分子激光虽然是一种精密的切割方法,但有些问题却限制了它的使用: (1)为了准确地切割100μm宽的角膜切口,在曝光过程中眼球必须完全固定,在20 Trokel et al. (1983) first used an excimer laser that emits radiation in the deep ultraviolet region (193 nm). The penetration of this radiation is about 1μm, can only produce very shallow about 300nm thermal damage zone. Although the excimer laser is a precise cutting method, some problems have limited its use: (1) In order to accurately cut a 100 μm wide corneal incision, the eyeball must be completely fixed during exposure and at 20