| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in which a signal light is reduced to lower an S/N ratio because a quantum efficiency in photo-electric conversion is as low as 50% or lower though there is a function of performing photo-electric conversion on a very weak light that is scattered by a flaw of the wafer surface to multiply the amount of the electrons in an inspection method such as PMT and MPPC that can measure the weak light quickly and with high sensitivity. <P>SOLUTION: Optical amplification is performed, which directly amplifies light before photo-electric conversion and is an amplification method in which signal light and light from an excitation light source are introduced into fiber optics to which rare earth is added, to cause induced emission to amplify the signal light. The optical amplification is used so that amplification factors vary depending on a variety of conditions. <P>COPYRIGHT: (C)2013,JPO&INPIT |
