Off-axis digital holographic measurement device capable of flexible zooming

Abstract

The invention relates to an off-axis digital holographic measurement device capable of flexible zooming, and the device is technically characterized in that a laser beam generated by a horizontal laser 1 is reflected by a first reflector 2, and an optical path is changed into a vertical path; the laser beam enters a beam-expanding collimation unit 3, and is reflected by a second reflector 4, and the optical path is changed into a horizontal optical path; and then the laser beam passes through an electric control zoom lens 5 and a microscopic objective lens 6 to enter a spectroscope, thereby generating two light waves, wherein one light wave is reflected by a plane mirror 8, and then serve as reference light to enter imaging equipment 10, and the other light wave is reflected by the surface of a measured object 9 and serves as objective light to enter the imaging equipment 10; the plane mirror 8 is adjusted so as to control the inclined angle between the reference light and the objective light, thereby enabling the objective light and the reference light to interfere with each other to generate an off-axis digital holographic image which is recorded by the imaging equipment 10; finally a numerical value reconfiguration algorithm is calculated and the information of the measured object. The device employs the electric control zoom lens 5, has a function of flexible zooming, avoids mechanical movement, greatly improves the adjustment speed and accuracy in an adjustment process of an amplification factor of a system, is compact and stable in structure, and can be used for the three-dimensional shape and appearance measurement of a micro-optic element, a microelectronic mechanical system and a micro-optical electro-mechanical system.

Description

technical field [0001] The invention relates to an off-axis digital holographic measurement device capable of flexibly variable magnification, and belongs to the technical field of laser digital holography and optical detection. Background technique [0002] The principle of digital holography is consistent with that of traditional optical holography, the difference is that the recording medium of the former is a photoelectric conversion device CCD or CMOS, which replaces the traditional holographic silver salt dry plate. The recorded hologram is stored in the computer in the form of a digital image, and then the diffraction process of the hologram is simulated according to the principle of digital holography, and the complex amplitude distribution of the object light wave is obtained by numerical reconstruction. Compared with traditional optical holography, the remarkable feature of digital holography is that it does not require chemical treatment processes such as developi...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of single system resolution, magnification and numerical aperture, poor operability, small working distance, cumbersome and inaccurate mechanical movement in the traditional lensless digital holographic detection device, and propose a flexible variable magnification off-axis digital holographic measurement device

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