Optical Coherence Microscopy Based On Dispersion Lens

The rapid development of precision manufacturing has made people more and more demanding of precision measurement technology.As an important displacement measurement tool in precision measurement technology,the displacement sensor not only has high precision and high anti-interference,but also needs real-time,non-destructive testing.The non-contact displacement sensor based on the principle of spectral confocal can measure the change of displacement without contacting the surface of the measured object.It has light weight,wide range,and strong adaptability to the measured target,in the field of engineering measurement and industrial production with good development prospects.Despite this,spectral confocal displacement sensors can only achieve sub-micron-level resolution.Optical coherence tomography based on Michelson interferometers has gradually become the key technology in the field ofmeasurement due to its high resolution and perspectivity.In this paper,based on comprehensive analysis of spectral confocal displacement sensor and optical coherence tomography displacement measurement technology,an optical coherence microscopy imaging technology based on dispersive lens is proposed,which has the advantages of large-range and high-precision.This paper introduces the principle of optical coherence tomography and analyzes the technical foundation of its ability to achieve nanoscale resolution displacement measurement.Then weelaborates the principle of spectral confocal displacement measurement and analyzes the important factors affecting the sensor performance and the key design techniques.At the same time,the ZEMAX optical design software was used to simulate the dispersive displacement lens.Finally,a highly sensitive phase-sensitive technique combined with a wide dynamic range displacement measurement method was developed based onthe fiber.The spectral multiplexing technique encodes the interference and spectral confocal signals,and then decodes the phase information of the interference signal based on the position information detected by the confocal signal to realize a displacement measurement system with nano-sensitivity and sub-millimeter dynamic range.