Masashi Yoshimura

Corneal ablation with new 193 nm solid-state laser: preliminary experiments.

PURPOSE: To assess the ability of a newly developed 193 nm solid‐state laser to ablate the cornea. SETTING: Osaka University, Osaka, Japan. METHODS: A prototype laser engine was developed by combining a 1547 nm laser diode, fiber amplifiers, and 5 stages of a frequency‐conversion system using CsLiB6O10 crystals as the last stage. Poly(methyl methacrylate) (PMMA) plates were exposed to the prototype laser beam to determine the relationship between the fluence and ablation rate. Laser irradiation of porcine corneas was performed to induce morphological changes, and the quality of the lesions was determined by light and scanning electron microscopy. RESULTS: The relationship between the fluence and ablation rate of the 193 nm solid‐state laser was comparable to that of the argon–fluoride excimer laser. Light and scanning electron microscopy of the porcine corneas showed that the linear and square lesions had sharp, clean edges. CONCLUSIONS: Smooth ablations of PMMA plates and porcine corneas were obtained by the laser. Further investigations must be conducted to determine whether this laser can be an alternative laser source for keratorefractive surgery.

Effective solid-state stimulated Brillouin scattering mirror by organic crystals LAP, DLAP

Stimulated Brillouin scattering phase conjugate mirror (SBS-PC mirror) by DLAP showed maximum reflectivity of 78 % at 1064 nm. Good SBS-PC fidelity in LAP and DLAP were also obtained by using 10 Hz Nd;YAG laser.