| 摘要 |
PROBLEM TO BE SOLVED: To provide an ATR element that can accurately identify the state of a substance by using measuring light in an infrared range even if the substance has only a low absorption coefficient for the measuring light.SOLUTION: An ATR element 10 comprises an element body having a reflecting face 13 continuous in the circumferential direction, an incidence face 19 that causes the element body 11 to let measuring light DL come into incidence on the incidence face 19, and a light emitting face 21 from which the measuring light DL reflected by the reflecting face 13 of the element body 11 is emitted externally. The measuring light DL coming incident from the incidence face 19 follows a spiral passage route while repeating reflection by the reflecting face 13 and reaches a second end face 17. The measuring light DL is reflected here, and then follows a spiral passage route while repeating reflection by the reflecting face 13 toward a first end face 15, and is emitted externally from the light emitting face 21. |
