Research On Scattering Measurement Technology

This topic is based on weak photoelectric signal detection principle the differential scattering measurement theory as theoretical guidance theoretical analysis for the relationship between the sample surface roughness and scattering. Through the photoelectric detector within the half spherical sample surface in any direction of scattering light detection, so that get the amount of space scattering distribution point, and then get the sample quality related information. In order to improve the system measurement range, though select PIN photodiode and APD avalanche photodiode in light of circumstances and choose PMT photomultiplier tube in the case of weak light.This subject mainly research the light source under the condition of fixed incident, to establsh differential scattering measurement system in the space of single point measuring the amount of scattering. Design the amplifier circuit can control regulation of the measurement system and made PCB circuit board. For the noise using band-pass filter to remove the background and other factors will bring in the extraction of weak signal, photoelectric detector as the core, under the guidance of the theory of differential scattering to accomplish each experiment module design and integration. Based on virtual instrument Lab VIEW as the development environment, operational amplifier and photoelectric detection technology was adopted to realize automatic control signal detection, signal detection and processing. Research contents include the design of optical system, selection of photodetector (probe measurement dynamic range and higher signal-to-noise ratio), strong background light to extract the weak signal.The mainly studies based on the measurement priciple of the differential scattering, using computer automatic control of the differential measurement system. It can get the scattering sample surface of spatial distribution. The method can not only understand the microscopic characteristics of sample surface, but also the use of automatic measurement system. This system can reduce the operation steps and has good repeatability, the measurement system achieves probe power of minimum verification which is1.628×10-6mw, measurement of the maximum error within±3%...