摘要
针对单波长Mirau干涉显微镜存在测量范围小和2π模糊等问题,提出了多波长Mirau偏振干涉显微镜,以实现微观轮廓的大动态范围测量的和表面粗糙度等显微结构的瞬态检测。系统利用R、G、B三个单色LED光源实现多波长干涉;利用彩色偏振相机获取瞬态相移干涉条纹图,降低实时瞬态检测中复杂的环境扰动影响;利用线栅偏振片调节条纹对比度,满足不同被测对象的反射率检测要求。为验证系统方案的可行性,经过系统误差补偿校准后测量标称值为1.9939μm的标准微米台阶,结果与标称值的偏差约为5.4 nm。利用该方法与Wyko干涉仪对金刚石车削凸面反射镜表面微观轮廓和表面粗糙度进行测量,表面粗糙度测量结果均方根值偏差为3.7 nm,验证了该系统可实现高精度的大动态范围测量。
Micro-optical components have been widely adopted in intelligent device imaging,medical devices,and national defense security due to their high degree of freedom and arrayability.The inspection is particularly important to ensure processing accuracy prior to use.Interferometric microscopy is the authoritative high-precision micro-profile inspection technology.However,the measurement range of single wavelength interferometry is limited by the wavelength,making it insufficient to detect optical devices with high degrees of freedom.Moreover,the traditional PZT phase shift is vulnerable to environmental disturbances and can cause drive hysteresis when measuring at multiple wavelengths.The multi-wavelength polarization Mirau interference microscope for transient micro profile detection is proposed to address the issues of narrow measurement range and 2πambiguity in single wavelength Mirau interference microscopes,enabling the testing of surface figure with large dynamic range and surface roughness of microscopic structures.It provides a simple and elegant solution to these problems that arise in the aforementioned interferometric microscopy measurements.This measurement system utilizes a splitter prism to gather three monochromatic LEDs as a multi-wavelength light source.In order to meet the testing requirements for various tested objects with different reflectivity,a linear grid polarizer is employed as a polarized beam splitter in the proposed system,to achieve polarization splitting and adjustable fringe contrast.The color polarization camera only needs to capture one image to decompose and obtain color phase-shifting interference fringes with a phase shift ofπ/2 in the three RGB channels.By using a four step phase shifting algorithm to calculate the transient wavefront distribution corresponding to the three wavelengths R,G,and B.Based on multi-wavelength interference technology,the accurate optical path difference between the reference light and the detection light at each pixel point can be obtained,thereby ac
作者
龚玉婷
吕鑫
刘维
孔明
GONG Yuting;LYU Xin;LIU Wei;KONG Ming(College of Metrology and Measurement Engineering,China Jiliang University,Hangzhou 310018,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2024年第1期57-65,共9页
Acta Photonica Sinica
基金
浙江省自然科学基金(No.LY21E050016)
国家自然科学基金(No.51775528)。
关键词
多波长干涉
瞬态检测
偏振成像
Mirau干涉显微镜
误差校正
Multi-wavelengths interferometry
Transient measurement
Polarization imaging
Mirau interference microscope
Error calibration
