Multi-wavelength tunable micro-interference measuring method and device thereof

Abstract

The present invention discloses a multi-wavelength tunable micro-interference measuring method and a device thereof. A multi-wavelength tunable laser is modulated to output three paths of wavelength tunable laser signals in the synchronous or time-sharing manner. The three paths of wavelength tunable laser signals are compounded as one path of composite laser signals through beam-combining optical fibers, and the path of composite laser signals is focused and coupled to the surface of a frosted glass plate which is rotating at a constant speed. After that, the path of composite laser signals is incident to the surface of a beam splitter after being formed as the parallel light through a collimating beam-expanding lens. The light is reflected to enter an interference microscope, and then is irradiated onto the surface of a to-be-tested element on an objective table. A reflected signal sequentially passes through the objective lens of the interference microscope and the beam splitter to be coupled to the target surface of a color camera through an imaging lens. Finally, output signals are regulated and acquired data are synchronously controlled by a computer. According to the technical scheme of the invention, a plurality of different wavelengths are adopted by a single-wavelength tunable laser module, so that the optical phase shift and the multi-wavelength interference detection are realized. The method and the device are especially suitable for the fast and accurate measurement of microstructure elements which are complex and non-continuous in surface shape variation. Therefore, measurement errors, caused by the scanning motion of a mechanical component, can be effectively inhibited.

Description

technical field [0001] The invention relates to a method and device for microscopic light interference measurement, in particular to a measurement device and method using multi-wavelength tunable microscopic interference, which belongs to the field of advanced manufacturing and detection technology. Background technique [0002] In the design and development of optoelectronic systems, it is often necessary to use a variety of optical components of different types and materials to improve system performance. The surface of some of these components (such as gratings) has complex microstructures formed by processes such as machining, plasma etching, and spray coating; , residual stress, service life, microscopic physical properties and other intrinsic characteristics are closely related. In order to effectively process the above-mentioned devices and make them better meet the design and application requirements of optoelectronic systems, it is necessary to conduct precise insp...

AI Technical Summary

Problems solved by technology

At present, for the surface microstructure of optical parts, ultra-precision detection combined with dual / multi-wavelength interferometry technology has yet to be carried out.

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