Topography And Edge Compound Measuring Probe System

In order to design a topography and edge compound measuring probe system,which can be combined with measurements such as topography,edge and height,the following tasks are mainly completed in this paper:1、An optical system based on the principle of interference was designed and built.The three-dimensional reconstruction of the microscopic surface topography to be measured through the Linnik phase-shifting interference,the five-step phase-shifting method was adopted to extract phase and the Goldstein algorithm was used to unwrap the phase.2、The confocal optical system with the core of the Blue-ray DVD pick-up head was designed.The height was measured through calibrating the focus error signal(FES).The position of the focal plane could be quickly adjusted by assessing of the focus error signal size.The edge detection model was established through the sum signal(SS),and the edge position can be determined by setting the proper threshold..3、Asemiconductor laser automatic power control(APC)module was designed and built based on the principle of feedback regulation of light intensity.According to the characteristics of the output signal of the pick-up head,a signal processing circuit of four quadrant sensor was designed and built..4、The phase shifter was designed and fabricated by using the piezoelectric ceramic(PZT)and Beryllium bronze.The best linear interval of PZT was also selected.Then the precise phase shift of the reference mirror is driven by calibrating the relationship between the voltage and displacement of the phase shifter.5、The experiments were carried out in a constant temperature chamber(20 ± 0.2 ℃)and the vibration platform was used for placement of the devices.The heights of 4 mm and 6 mm were measured,whose standard deviations were 44 nm and 53 nm respectively.Width of the metal block and diameter of the micro hole were measured,whose standard deviations were 88 nm and 49 nm respectively.The surface topography of the standard grid,mirror and steel ball were measured,their three-dimensional reconstruction can be obtained.Finally,the probe system errors were analyzed.