| 摘要 |
PURPOSE: To provide the opto-acoustic infrared detector, which improves the detecting sensitivity of infrared rays. CONSTITUTION: In an opto-acoustic infrared detector, which measures the amplitude of the vibration of a film 9 by heat caused by the absorption of infrared rays and detects the intensity of the absorption of the infrared rays, the reflecting surface of a prism 11 is arranged so as to face the film 9, and a high part 13 having the small area is provided at the at least one of the reflecting surface of the prism 11 and the film 9. The prism surface or the upper surface of the height part 13 on the prism is made to be a total reflecting surface 14. The upper surface of the high part 13 is arranged with the minute gap being provided with the facing surface. Measuring light 22 is made into linearly polarized light containing the S-polarized light and the P-polarized light by a polarizer 19, and the light is reflected from the total reflecting surface 14. Then, the phase difference between the S-polarized light and the P-polarized light is changed into the intensity of the measuring light with an analyzer 20. The change in intensity is converted into the electric signal with a photodiode 23, and the intensity of the absorption of the infrared rays caused by chemical material is detected. |
