An optical sensor is a device that utilizes optical principles to convert optical signals into electrical signals, thereby detecting and measuring physical quantities. Point chromatic confocal sensors analyze the wavelength distribution of light, enabling material composition analysis, color detection, and more. Point laser sensors leverage the directionality and monochromaticity of laser beams to perform high-precision displacement and distance measurements with fast response speeds. White-light interference sensors, based on the principle of interference, offer extremely high precision for measuring micro-displacements and surface topography, achieving nanoscale resolution.

Point spectral sensors are widely used across multiple industries, with core applications including the following fields:

• In the food testing industry: They can detect the composition (e.g., protein, fat, sugar content in grains, dairy products, or beverages) and freshness (e.g., judging the ripeness of fruits, the spoilage degree of meat, or the shelf-life status of aquatic products) of food, helping to ensure food safety and quality consistency.
• In the pharmaceutical sector: These sensors are applied to pharmaceutical component analysis (e.g., verifying the purity of active pharmaceutical ingredients (APIs) or detecting trace impurities in drugs) and quality monitoring (e.g., real-time monitoring of drug particle size distribution during production or confirming the uniformity of drug formulations), complying with strict pharmaceutical industry standards (such as GMP).
• In environmental monitoring: They enable the detection of atmospheric pollutant components (e.g., measuring concentrations of nitrogen oxides, sulfur dioxide, or volatile organic compounds (VOCs) in the air) and water quality parameters (e.g., analyzing dissolved oxygen, COD (Chemical Oxygen Demand), or heavy metal content in water bodies), providing data support for environmental protection and pollution control.
• In industries such as textile and printing: Point spectral sensors are used for color matching (e.g., aligning the color of textile fabrics with design standards or ensuring consistency between printed patterns and original samples) and quality control (e.g., identifying color deviations or uneven dyeing on product surfaces), ensuring that the color of final products meets customer or industry specifications.

1. Environmental interference: Strong ambient light (e.g., sunlight, bright LEDs) overlaps with laser signals; temperature fluctuations deform internal components; vibration displaces the sensor/target.
2. Target surface properties: High reflectivity (polished metal/glass) causes specular reflection (weak signals); low reflectivity (matte black plastic) absorbs light; roughness scatters light; inclination makes laser spots elliptical.
3. Hardware/installation: Large laser divergence angles enlarge spots at long distances; working distances outside the optimal range reduce signal quality; uncalibrated sensors accumulate errors.

• Fight interference: Use light shields/optical filters for ambient light; choose temperature-compensated sensors and vibration-damping brackets.
• Adapt to surfaces: Pick near-infrared lasers for reflective targets, high-power lasers for low-reflectivity ones; align beams perpendicularly to targets (use angle mounts).
• Optimize setup: Select small divergence angles for short-distance measurements; keep working distances optimal; calibrate every 3–6 months with standard targets.

       White-light interference sensors are particularly suitable for measuring samples with complex and tiny surface topographies, such as surface defects of semiconductor chips, surface flatness of optical lenses, and structures of microelectromechanical systems (MEMS) devices. They can also be used to measure thin film thickness, such as the coating thickness of mobile phone screens and the thin film thickness of solar cells, and are capable of providing high-precision 3D topography data.