Products >> Sensors, transmitters >> Optical sensor

Optical sensors utilize optical phenomena and principles such as light propagation, reflection, refraction, absorption, scattering, interference, and diffraction. They convert the change of the measured quantity into a change of the optical signal. Then, through a photoelectric conversion element, the optical signal is converted into an electrical signal, thus realizing the detection and measurement of the measured quantity. For example, in some optical sensors for distance measurement, the light emitted by the transmitting light source irradiates the target object and then reflects back. The sensor calculates the distance between the target object and the sensor according to information such as the round - trip time of the light or the intensity of the reflected light.
Characteristics:
- Non - contact Measurement: It doesn't directly contact the measured object, so it won't damage or interfere with the measured object. It's suitable for the measurement of fragile, breakable, and tiny objects.
- High Precision and High Sensitivity: It can detect tiny optical changes and has a high resolution and sensitivity to the change of the measured parameter.
- Fast Response: The high speed of light enables the optical sensor to respond quickly to the change of the measured parameter, so it's suitable for dynamic measurement and real - time monitoring.
- Immune to Electromagnetic Interference: In complex electromagnetic environments, optical sensors have good stability and reliability.
- Multi - parameter Measurement: By choosing different light sources, optical elements, and detection methods, it can measure multiple physical quantities such as distance, displacement, speed, angle, temperature, pressure, and concentration.
Classification:
- Photoelectric Sensor: Based on the photoelectric effect, it converts an optical signal into an electrical signal. Common ones include photoresistors, photodiodes, phototransistors, and photocells. For example, in an automatic lighting control system, a photoresistor as a photoelectric sensor automatically adjusts the brightness of the light according to the change of ambient light intensity.
- Fiber - optic Sensor: Using optical fiber as the transmission medium and sensitive element, it detects the measured quantity according to the characteristic change of light propagation in the fiber. For example, fiber - grating sensors can be used to measure physical quantities such as temperature and strain and are widely used in the health monitoring of large - scale structures such as bridges and tunnels.
- Spectral Sensor: By analyzing the absorption, emission, or scattering characteristics of substances to different wavelengths of light, it determines the composition and concentration of substances. For example, in environmental monitoring, spectral sensors can be used to detect the concentration of pollutants in the air.
- Image Sensor: It can convert an optical image into an electrical signal. Common ones include Charge - Coupled Device (CCD) image sensors and Complementary Metal - Oxide - Semiconductor (CMOS) image sensors. They are widely used in digital cameras, video cameras, surveillance cameras, and other equipment.

Mainstream Brands

Foreign Brands:
- Analog Devices (ADI): It provides integrated ultra - low - noise amplifiers and high - performance photodiodes and other optical sensor products. They are used in instruments, industry, and clinical fields and are known for high performance and high reliability.
- Heidenhain: A German brand. Its optical sensors are widely used in the production and processing equipment of precision machine tools and electronic components. The products have the characteristics of high precision and high stability.
- Sick: A German multinational manufacturer of sensors and analytical instrument systems. It's one of the leaders in technology and market in the field of industrial automation. Its optical sensor products have a wide variety and excellent performance.
- Omron: A Japanese manufacturer of automation control and electronic equipment. It masters the world - leading core technology of sensing and control. Its optical sensors are widely used in industrial automation, electronic equipment, and other fields.
Domestic Brands:
- Changchun Yuheng Optics: It's one of the first batch of national high - tech enterprises recognized in Jilin Province. It's a professional manufacturer of grating encoders, optical instruments, and complete sets of electromechanical equipment. Its grating encoder products, as a kind of optical sensor, are widely used in the automation field.