| 摘要 |
<p>A subject apparatus comprises a laser source (11), a light-intensity adjustment (14), a polarizer (13), and a sensor (19). The laser source (11) emits a beam of laser light toward a sample (18), the light having a characteristic that generates a measurable response in the sample (18) whenever the sample receives an amount of the laser light. The light-intensity adjustment varies the intensity of the laser light directed to the sample. The polarizer polarizes the laser light directed to the sample. The sensor detects the response in the sample. The polarizer comprises first and second plates transmissive to the laser light. Each plate is oriented at an angle of incline relative to a plane perpendicular to the laser beam, the angle of incline for the first plate being opposite to the angle of incline for the second plate. At least one of the plates comprises a surficial film coating that transmits one of the components of the polarized light and reflects the other component. <IMAGE></p> |
