Line scanning light splitting white light interferometer

Abstract

The invention discloses a line scanning light splitting white light interferometer. The light source part comprises an SLD light source, wherein the light emitting end of the SLD light source is connected with a collimator; a light beam emitted by a light emitting end of the collimator enters a beam splitter prism after passing through a first cylindrical lens, and enters a reference arm and a sample arm in two paths respectively; reflected light returned by the reference arm and the sample arm enters a second telecentric lens after passing through the beam splitter prism and then enters a spectrograph; the reference arm is sequentially provided with a second cylindrical lens, an achromatic lens and a reflective mirror; and the sample arm is provided with a first telecentric lens, a measurement sample and a one-dimensional translation stage. The line scanning light splitting white light interferometer has the advantages that the adopted SLD light source is short in coherence length and high in power; the cylindrical mirror generates linear array light beams, so that linear scanning detection can be completed, and the detection precision is improved; the achromatic lens and the telecentric lens can be two lenses with different focal lengths, and the reference arm and the sample arm do not need to meet the aplanatism condition; and the telecentric lens can avoid dead angles, and has the advantages of high positioning precision and high energy uniformity.

Description

technical field [0001] The invention relates to the technical field of optical instruments, in particular to a line-scan spectroscopic white light interferometer. Background technique [0002] An interferometer is a precision instrument that accurately measures geometric height changes or refractive index changes through changes in the optical path difference between two beams of coherent light. Any change in the optical path difference between two beams of coherent light will very sensitively lead to the movement of the interference fringe, so the small change in the geometric length or refractive index can be measured through the movement of the interference fringe, and other related physical quantities can be measured. The high measurement accuracy is unmatched by any other measurement method. At this stage, there is an interferometer using white light as the light source. Its coherence length is short, the height measurement of the corresponding sample surface is more a...

AI Technical Summary

Problems solved by technology

However, the XY scanning galvanometer still needs two sets of mechanical rotation units to control the oscillating vibration of the galvanometer to realize scanning, which increases the error and affects the accuracy.

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