| 摘要 |
PURPOSE:To require no correction due to the difference of the sensitivity characteristic of a detector, the offset of an amplifier and the difference of a gain characteristic by detecting a 0-th order diffraction light and a 1st order diffraction light obtained according to the progress of a development by the use of one detector and amplifying by one amplifier. CONSTITUTION:Since a group is formed on the pattern face of a master optical disk 1 according to the progress of the development, the 0-th order diffraction light (b) obtained by irradiating a laser light (a) on the pattern face vertically is made incident on the detector 9 through a first shutter 7 and the 1st order diffraction light (c) through a second shutter 8, respectively. Then, the detector 9 detects the intensity of the diffraction light to output as a voltage signal (g) and have the input signal of a diffraction light ratio monitor part 111 as a diffraction light intensity signal (h) by the amplifier 10. Thereby, the correction of the difference of the sensitivity characteristics of the two detectors and the offset and the difference of the gain characteristics of the two amplifiers is not required. |
