SOLID-STATE LASER SOURCE FOR CORNEAL ABLATION

CORNEAL SCULPTING IS A NEW TECHNIQUE THAT USES AN ULTRAVIOLET LASER TO CORRECT REFRACTIVE VISION DISORDERS BY ABLATING A PORTION OF THE CORNEA. CURRENT CLINICAL SYSTEMS USE THE ARF EXCIMER LASER OPERATING AT 193 NM, WHICH PRODUCES SHARPLY DEFINED CORNEAL INCISIONS WITH MINIMAL DAMAGE TO ADJACENT TISSUE. THE DEVELOPMENT OF A SOLID-STATE ALTERNATIVE TO THE EXCIMER IS NOW POSSIBLE DUE TO ADVANCES IN THE GROWTH OF NON-LINEAR CRYSTALS WITH FAVORABLE UV PROPERTIES. BY USING A TUNABLE PULSED TI:SAPPHIRE LASER AS THE PUMP SOURCE, A WIDE RANGE OF UV WAVELENGTHS CAN BE GENERATED VIA NON-LINEAR FREQUENCY CONVERSION. AS PART OF THE PHASE I EFFORT, THE NEAR-IR OUTPUT OF A PULSED TI:SAPPHIRE LASER WILL BE CONVERTED TO THE 205-225 NM REGION VIA FREQUENCY QUADRUPLING IN TWO BETA-BARIUM BORATE CRYSTALS. THE OBJECTIVE OF THIS WORK IS TO DETERMINE WHETHER THE QUALITY OF THE CORNEAL INCISIONS MADE USING WAVELENGTHS RANGING FROM 205-225 NM COMPARE FAVORABLY WITH THOSE MADE BY THE 193 NM EXCIMER. IF A WAVELENGTH WITHIN THIS RANGE DOES PROVE TO BE USEFUL FOR CORNEAL ABLATION, THE LONG TERM GOAL OF THIS PROGRAM WOULD BE TO DEVELOP A CLINICALLY QUALIFIED SOLID-STATE LASER FOR REFRACTIVE SURGERY.