Research And Application Of Portable Optical Surface Profiler

With the inceasing development of advanced manufacturing, the extra precision of ultra-smooth surface measurement in micro-electronics, optical and mechanical industry is required. The on-line detection in industry is heightened the demand for stability, portability, and flexible and functionality of a testing instrment.Based on short-coherent light interference microscopic techniques and phase-shifting interferometric technique, a portable microscopic profilometer was designed and implemented. The optical and mechanical system is highly integrated to realize the fastness, real time and high accuracy detection of 3D microscopic surface detection.The system based on short-coherent light interference microscopic techniques realizes high accuracy detection of 3D microscopic surface. Combined with corresponding phase-shifting algorithm, the system can analyse microscopic profile and evaluation parameters towards 3D microscopic surface. The highly integrated system realize a smaller and enhanced stable stucture to improve system’s rejection capability towards vibration and airflow of the environment. The optimum design of 3D adjustment platform is intented to breaking the restrictions on the lateral dimensions of objects. Coaxial illumination system use a type of co-axial lighting for Kohler illumination with LED light source, which is modulated by interferometric filter.Micro-displacement system use piezoelectric ceramics as phase shifter to realize precise shifting. Different phase extraction algorithm is sensitive to different phase error. Based on the characteristics of the system, system use the overlapping average phase shifting algorithm to suppress the non-linear error caused by ambient noise.Finally, we use portable microscopic profilometer to carry on a large number of experiments, such as sapphire and silicon wafers’s ultra-smooth surface. After calculating of large amounts of data, we analyse lots of three-dimensional surface roughness parameters to verify the accuracy of the instrument. The instrument’s accuracy is up to 0.1nm, repeatability error is better than O.Olnm, the lateral resolution is better than 1μm. In addition,Nanjing Institute of Astronomical Optics Technology and Wuhu Optoelectronics Technology Co., Ltd use the instrument to resolve the problem of large optical telescope mirror and LED sapphire surface’s on-line detection.