Design of a chromatic confocal displacement sensor integrated with an optical laser head

Abstract

In this paper, the methodology for design of the system consisting of chromatic confocal displacement sensor integrated with an optical laser head was presented. Furthermore, the results of experimental characterization of optical components of the laser head were also included in the numerical analysis. The designed chromatic confocal displacement sensor was analyzed as an assembly of components widely available on the optical market. Nevertheless, the main goal of the numerical optimization was to determine the influence of individual components of the optical path of the system on its parameters, i.e., measuring range, FWHM of the characteristic spectral peak, and intensity that reaches the detector. The optimized solution was characterized in order to determine the calibration curve, as well as other important application parameters of the system. Moreover, taking into consideration the integration aspect the caustic of the laser beam shaped by the laser head was measured. Finally, the versatility of the system was presented and discussed.

Online Correction of Laser Head Nozzle Position for Laser Metal Deposition Using a Chromatic Confocal Displacement System

“…In order to determine the distance (L) between the laser head nozzle (LHN) and the substrate material (S), an optical system developed by the authors was used ( Figure 1 ). Its detailed description, in terms of operating principle, parameters, and functionality, has been presented in previous publications [ 21 , 22 ]. In brief, the optical system is a modified version of the chromatic confocal sensor (CCS), which is commonly used as a stand-alone displacement sensor.…”

Advantages and limits of spectrometer free areal chromatic confocal metrology

“…In contrast to areal CCM sensors, point and line CCM sensors are used in different medical, research and industry applications. [3][4][5][6] The ChromaCAM system uses a single-shot technique based on the intensity measurement of two CMOS sensors and a simple image processing algorithm. These two characteristics combined enables this sensor to measure the surfaces of various materials at high frame rates.…”

Toward areal chromatic confocal metrology

“…Nevertheless, a limitation for the simultaneous acquisition of multiple measurement points still persists: the spectrum of the reflected light has to be analyzed to obtain the surface height information, which creates the need for an additional spatial dimension to expand and transform the light spectrum into the spatial domain. Multiple approaches utilizing prism 2 or grating-based spectrometer setups and the application of multi spectral cameras 9 , 10 or mechanical devices and hybrid systems 9 , 11 – 16 have been employed to analyze the reflected light spectrum.…”