Spectrum confocal measurement system calibrating device and calibrating method

Abstract

The invention discloses a spectrum confocal measurement system calibrating device and calibrating method. The spectrum confocal measurement system calibrating device comprises a tunable laser, a double-branch optical fiber, an optical fiber emergent light beam, a dispersion object lens, a dispersion object lens emergent light beam, an object to be detected, a displacement table, a spectrometer and a computer. The spectrum confocal measurement system calibrating method comprises steps of recording a position of a detected object, on which a displacement is applied, through a displacement sensor, setting an output wavelength range of the tunable laser to enable the tunable laser to successively emit monochromatic laser beams covering a working waveband of the dispersion object lens, recording the size of the wavelength of the laser beam emitted by the tunable laser in the current lambda and a spectrum signal having a biggest amplitude in the spectrometer and a pixel number n corresponding to a peak value position of the spectrum signal, and establishing a relation between a wavelength and displacement of the detected object through a correspondence relation between the n and the lambda. The spectrum confocal measurement system calibrating device and calibrating method effectively reduce requirements of the dispersion object lens for linearity in the spectrum confocal measurement system and improves measurement accuracy of the spectrum confocal measurement system.

Description

technical field [0001] The invention relates to the technical field of optical measurement, in particular to the calibration of a spectral confocal measurement system. Background technique [0002] The spectral confocal method is a non-contact micro-displacement measurement method based on wavelength displacement modulation. It has the advantages of high measurement accuracy, fast speed, insensitivity to the texture and inclination of the measured surface, and no special requirements for materials. It has important application and development prospects in precision engineering such as manufacturing and ultra-precision manufacturing, micro-machines, micro- and ultra-fine processing. [0003] There are many factors that affect the measurement accuracy of the spectral confocal system, such as the resolution of the spectrometer, the linearity of the dispersive objective lens, etc., usually need to be specially designed and individually calibrated for each factor that affects the...

AI Technical Summary

Problems solved by technology

However, it is difficult to achieve ideal linear dispersion objective lens in practice. First, it is difficult to design an ideal linear dispersion objective lens in the optical design stage. Secondly, even if a dispersion objective lens with good linearity is designed, due to the dispersion objective lens Inevitable errors in the process of processing, coating, and assembly will also deteriorate the linearity of the dispersion objective lens

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