| 摘要 |
PURPOSE:To measure a dynamic beam profile of a light beam simply by engaging an optoelectro transducer means with a light shielding plate having one set or more of openings and the openings corresponding to a direction of main scanning. CONSTITUTION:Laser light L1 outputted from a laser diode 2 is reflected on a reflecting surface 6a of a galvanometer mirror 6 oscillating through a collimator 4 to irradiate almost perpendicularly to slits 54a and 54b on a light shielding plate 56 through an ftheta lens 8. The laser light L1 passing through the slits 54a and 54b is converted to electricity from light with an optoelectro transducer section 58 and an current signal corresponding to the intensity of the laser light L1 is introduced into a current/voltage conversion circuit 90. The current signal is converted into a voltage signal to be introduced into an oscilloscope 94 through an amplifier 92. An interval is measured corresponding to a beam diameter at a point where an interval and amplitude value of a waveform correspond to 1/e<2>(e 2.72) from the waveform on a tube surface of the oscilloscope. This simplifies measurement of a dynamic beam profile of the light beam. |
