| 摘要 |
PURPOSE:To minimize the length of an optical path and to scale down a detector by arranging a beam splitter between a light source and a collimator lens and disposing a critical angle prism on a reciprocating optical path between the collimator lens and an objective one. CONSTITUTION:The critical angle prism 5 and the polarization beam splitter 2 are arranged on the reciprocating optical paths between the collimator lens 4 and the objective lens 7 and the space between the light source 1 and the collimator lens 4, respectively. Simultaneously a photodetector 9 is arranged away from the conjugate position of the light source 1 with respect to the collimator lens 4. Then the flux from the light source 1 is irradiated on an object through the beam splitter 2, the collimate lens 4, the critical angle prism 5 and the objective lens 7, and the photodetector 9 is so constituted to receive the reflected light through the objective lens 7, the critical angle lens 5, the collimator lens 4 and the beam splitter 2. Thus the length of the optical path can be minimized to reduce the number of parts, whereby the detector can be scaled down. |
