LASER BEAM MONITOR FOR LASER SYSTEM

• Main Author: TSUCHIDA KAZUTERU
• Format: Patent
• Language: English
• Published: 17.04.1989
• Subjects: BASIC ELECTRIC ELEMENTS; COLORIMETRY; DEVICES USING STIMULATED EMISSION; ELECTRICITY; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PHYSICS; RADIATION PYROMETRY; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

PURPOSE:To detect the position of a laser beam and a laser mode by distributing and introducing the beam to a coaxial ring divided type laser beam detector having a photodetector of a center and a photodetector disposed in a ring state around the center and divided circumferentially. CONSTITUTION:In a coaxial ring divided type laser beam detector (CR type PD) 1, the intensity of a signal from a circular photodetector of a center is 10, and the intensities of signals from divided ring detectors of a periphery are I1,i (i=1-4). After a laser system is regulated, a reflected laser light 9 from the surface of an amplifier 7 is incident through a lens 8 to the CR type PD 1, the intensities I0, I1,i in this case are stored in a computer, and utilized in case of measuring a laser mode. That is, since the I1,i (i=1-4) take different values when a laser optical path is varied, a mirror 5 is so regulated that they become equal. If the regulation of a laser oscillator and the like is broken or the laser mode is destroyed due to the damage of the mirror or the like, the ratio of the I0 to the I1,i is varied. Thus, it is detected to automatically notify a malfunction.