| 摘要 |
PURPOSE:To increase the signal intensity of a differential waveform more than that in a conventional method, by improving the shape and vibrating method of a vibrating mirror. CONSTITUTION:The vibrating mirror 5 has a configuration wherein two mirrors are combined so that a constant angle alpha (corresponding to a rotary angle in the conventional method) is provided views from the direction perpendicular to a beam (perpendicular to the paper). The mirror 5 is vibrated in the direction perpendicular to the paper at a constant vibration number omega. Then, the modulating component becomes a rectangular wave having a vibrating frequency omega and an amplitude (a), instead of a modulating signal (a sin omegat) in the conventional method as shown by a signal 12. Therefore said crossing curves becomes the shape shown by a curve 13. When the intensities of the differential waves are compared, the intensity of this method is pi/2 times that of the conventional method, at the part where the intensity distribution curve 7 of the primary signal is linear. The intensity of the differential wave of this method is always larger at any part of the curve 7. |
