Traditional chromatic confocal measurement primarily relies on single-point detection, resulting in low efficiency, as each measurement cycle yields only the axial height of a single point. To enhance measurement efficiency, we propose a line-array spectral confocal measurement system. The system uses a 7-channel fiber bundle as an optical beam-splitting device to achieve a 2 mm linear measurement range for line-array illumination. A custom-designed dispersive objective lens generates a 2.5 mm spot, and an area-scan spectrometer, composed of a reflective grating and an area-scan camera, replaces the conventional spectrometer to enable simultaneous processing of multi-point spectral signals. Experimental results demonstrate that the system achieves an axial measurement range of approximately 200 μm, a repeatability within 0.95 μm, a lateral resolution of 1.183 μm, and an axial resolution of 2.287 μm, with measurement accuracy at the micrometer level.

To improve measurement efficiency, we propose a measurement system based on line-array spectral confocal technology. A fiber bundle is used as the optical splitter to focus multiple beams onto the surface of the measured sample, thus enabling line-array parallel illumination. A spectrometer system consisting of a reflective grating and an area-scan camera replaces the traditional spectrometer to receive and process multi-point spectral signals. In addition, a data processing method based on virtual grid transformation is designed. This method allows for the adjustment of the virtual grid size according to the actual experimental conditions, making it adaptable to different measurement requirements. A series of experimental studies are conducted on the constructed measurement system: 1) System calibration: A flat mirror is used to determine the system’s axial measurement range and to establish a mapping between virtual grid positions and axial displacement. 2) Reproducibility test: Multiple measurements at varying axial positions verify the system’s stability and reproducibility. 3) Step height measurement: Gauge blocks are used to simulate step samples, validating axial resolution and accuracy. 4) 3D surface reconstruction: Step samples are reconstructed in 3D to evaluate the system’s capability in surface morphology recovery.

The system calibration experiment determines that the system’s axial measurement range is 0?200 μm. Compared to traditional single-point methods, the proposed system improves measurement speed by approximately sevenfold, attributed to the fiber bundle’s line-array illumination which enables simultaneous multi-point data acquisition. The measurement accuracy of the system reaches the micrometer level, indicating that the signal reception device and data processing algorithm used effectively enhance the reliability of the measurement results. In reproducibility tests, standard deviation remains under 0.95 μm, demonstrating excellent stability and reliability. This result indicates that the line-array spectral confocal measurement system maintains high consistency across multiple measurements, making it suitable for precise surface profile measurements. In the 3D reconstruction of the step surface, the system’s axial resolution and measurement accuracy are validated, with a population standard deviation of less than 1 μm. The system successfully reconstructs the object’s surface morphology, with the reconstruction results aligning with the design specifications. These findings confirm the system’s effectiveness and applicability in real-world scenarios, particularly where high-resolution surface profile data is required. The virtual grid transformation algorithm significantly improves data processing accuracy. It also offers strong flexibility, allowing the system to adapt to various measurement conditions and enhancing its dynamic response capability.

In this paper, we propose a novel line-array spectral confocal measurement system that replaces the traditional single-point fiber with a fiber bundle to realize multi-point, line-array detection. The system integrates a spectrometer structure composed of a reflective grating and an area-scan camera for synchronous multi-point spectral acquisition. A virtual grid transformation algorithm is developed for data processing, tailored to the characteristics of the captured images. Experimental validation confirms that the system improves measurement efficiency by a factor of seven compared to conventional methods. It achieves an axial measurement range of approximately 200 μm, with reproducibility under 0.95 μm and micrometer-level resolution. The system successfully reconstructs step morphologies in 3D, demonstrating its robustness and applicability in precision surface metrology.