Orthogonal homodyne laser interferometer and measurement method thereof

Abstract

The invention discloses an orthogonal homodyne laser interferometer and a measurement method thereof. The interferometer is simple and reliable in structure, and comprises a helium-neon laser, a beam splitter prism, a lambda / 8 wave plate, a cubic pyramid prism, a measuring cubic pyramid prism, a precision guide rail, a photoelectric detector, a small signal amplification module, a band-pass filter module, an analog-to-digital conversion unit and a computer data processing unit. According to the invention, laser light emitting by the laser is split into reference light and measuring light after passing through the beam splitter prism, the measuring light firstly passes through the lambda / 8 wave plate and is then reflected by the measuring cubic pyramid prism so as to acquire a light beam, the light beam passes through the lambda / 8 wave plate again and generates interference with a reference light beam reflected by a reference cubic pyramid prism, and finally, two paths of orthogonal polarized light are acquired after passing through a polarization splitting prism; the photoelectric detector receives light signals and converts the light signals into electric signals, and signal conditioning is carried out by an amplification and filtering module; and the analog-to-digital conversion unit is controlled by a computer unit to acquire the conditioned electric signals, the phase is demodulated, and the real-time displacement of the measuring cubic pyramid prism is acquired and displayed.

Description

technical field [0001] The invention relates to the technical field of precise displacement measurement, in particular to a homodyne laser interferometer with high resolution and large measurement range and a measurement method thereof. Background technique [0002] Displacement is one of the most basic geometric parameters, and its accurate measurement is of great significance for people to engage in research in various fields and promote scientific progress. On the one hand, compared with other mechanical quantities, displacement is easy to detect, and the detection accuracy is high, so the mechanical quantity of the measured object is often converted into displacement for detection, and displacement measuring instruments have therefore become the most basic measurement of mechanical quantity measuring instruments instrument. On the other hand, the rapid development of nanotechnology in recent years, especially the rapid development of semiconductor technology, microelect...

AI Technical Summary

Problems solved by technology

However, this type of interferometer is large in size, heavy in weight, requires a lot of optical components and complex optical signal detection devices, so it is difficult to make a compact and low-cost measuring instrument

[0004] Traditional interferometry structures generally have large systems, complex optical paths, are sensitive to collimation, and are expensive. Therefore, there is an urgent need for a simpler, more compact, and more stable interferometric displacement measurement system.

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