Laser Beam Calibration and Beam Quality Measurement in Laser Surgery Systems

摘要

A laser eye surgery system includes a computer which scans a focused laser beam in a trajectory over a reticle or target and determines beam quality via laser light reflected from the target. The target may have a grid pattern of lines, with the diameter of the focused laser beam determined based on a time interval for the scanned beam to move onto a line of the grid pattern. Methods for measuring beam quality in a laser eye surgery system provide a direct, quantitative quality measurement of the focused laser beam, and may be performed quickly and automatically. Using scanning mirror position information together with signals resulting from laser light reflected from the target, the laser eye surgery system may also be calibrated.

主权项

1. A method for determining the diameter of a focused laser beam in a laser eye surgery system, comprising:
scanning the focused laser beam over a first line at a first position on a target; sensing laser light reflected or scattered by the first line as the focused laser beam crosses onto the first line; providing a first sensed light signal based on the sensed reflected laser light; calculating a first diameter of the focused laser beam at the first position based on the sensed light signal and a scanning velocity of the focused laser beam at the first position; and scanning the focused laser beam over a second line at a second position on the target; sensing laser light reflected or scattered by the second line as the focused laser beam crosses onto the second line; providing a second sensed light signal based on based the light sensed as the focused laser beam crosses onto the second line; calculating a second diameter of the focused laser beam at the second position based on the second sensed light signal and a scanning velocity of the focused laser beam at the second position; displaying a beam quality indicator based on the first diameter and the second diameter.