Reflective type phase shift digital holography device based on light splitting pupil and method

Abstract

The invention relates to a reflective type phase shift digital holography device based on a light splitting pupil and a method. The method comprises the following steps of enabling parallel incident light to pass through a polarizer and a 1 / 4 wave plate and form elliptical polarizing light, and splitting into two beams by a polarizing light splitting prism; after one light beam is reflected by a first reflector, radiating to the polarizing light splitting prism; after the other light beam passes through a first lens, an entry pupil of the light splitting pupil and an objective lens, slantwiseradiating to the to-be-tested object in parallel, reflecting by the to-be-tested object, sequentially passing through the objective lens, an exit pupil of the light splitting pupil, a second reflectorand a second lens, and radiating to the polarizing light splitting prism; enabling two light beams combined by the polarizing light splitting prism to pass through a second polarizer, and generate interference on a plane of the image sensor so as to form an interference map; rotating the first polarizer to form a phase shift interference map, collecting by the image sensor, and uploading to a computer; utilizing the computer to calculate the phase of the to-be-tested object. The method has the advantages that the structure is simple; the three-dimensional scanning structure is not needed; themethod is more suitable for the full-field quantitative three-dimensional measuring on the scattered object.

Description

technical field [0001] The invention belongs to the field of digital holographic detection, in particular to a reflective phase-shift digital holographic device and method based on split pupils. Background technique [0002] Digital holography is a non-contact, high-precision full-field quantitative three-dimensional measurement method, which is widely used in optical surface deformation, thickness and cell measurement. Digital holography is based on the principle of interference, and off-axis methods, time phase shift methods, and synchronous phase shift methods are often used. Off-axis interferometry, by introducing an inclination angle between the object light and the reference light, the interferogram generates a carrier wave, thereby separating the items required to recover the phase from the interference items, and using an interferogram to recover the phase of the object to be measured , has strong real-time performance, but the space bandwidth utilization rate of th...

AI Technical Summary

Problems solved by technology

However, the device adopts the optical focusing point measurement structure, which not only has a complex structure, high cost, but also poor real-time performance when completing three-dimensional measurement.

Images