| 摘要 |
<p>PURPOSE:To detect a weak scattered light effectively, by a method wherein the scattered light is condensed with a cylindrical lens in a 1-D direction and further to one point with an optical fiber plate. CONSTITUTION:A laser 2 is reduced to irradiate to a point on a sample 1 to scan it in the direction of the arrow. When a foreign matter exists, scattered light is generated and condensed vertically with a cylindrical lens 4. Right and left scattered light is reflected with flat mirrors 5 and 6 to prevent the expanse thereof horizontally. Moreover, Al is deposited on sides 20 and 21 to prevent horizontal expanse of the scattered light. An optical fiber plate 7 is provided on an imaging surface of the cylindrical lens 4 and light thereby condensing light to one point to be converted into an electrical signal with an optoelectric transducer 8.</p> |
