Spectral confocal displacement sensors are precision measurement devices that utilize spectral confocal principles to achieve non-contact displacement measurement through optical systems and spectroscopic techniques. Their core functionality is based on spectral confocal technology, combining the depth resolution capability of “confocal imaging” with the wavelength encoding characteristics of “white light dispersion.”

I. Working Principle

1. White Light Dispersion: The sensor emits a broad-spectrum white light beam (containing multiple wavelengths). Through a specially designed dispersion lens (such as an achromatic lens group), light of different wavelengths is focused at different positions along the optical axis (short wavelengths focus closer, long wavelengths focus farther).

2. Confocal Positioning: When the surface of the measured object is located at a specific focal position, only the light corresponding to that wavelength is reflected back to the detector. Light of other wavelengths is suppressed due to defocusing.

3. Spectral Analysis: Reflected light is dispersed into a spectrum by a dispersive device (such as a grating or prism). A spectrometer or photodetector array detects the peak wavelength. Using a calibration curve (correspondence between wavelength and distance), the precise position or displacement of the object's surface can be calculated.

II. Technical Features

• High precision: Achieves sub-micron or even nanometer-level resolution.

• Non-contact measurement: Prevents damage or interference to the measured object.

• Adaptable to diverse materials: Measures metals, ceramics, glass, transparent/translucent materials (e.g., films, liquid surfaces), and even multilayer structures.

• Resistant to tilt interference: Insensitive to measurement angles, enabling stable measurements on inclined surfaces.

• Rapid response: Suitable for dynamic measurement scenarios (e.g., vibration detection).