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.