A laser sensor refers to a sensor that uses laser technology for measurement. It consists of a laser, a laser detector, and a measurement circuit.Laser sensors are a new type of measuring instrument, with advantages such as enabling non-contact long-distance measurements, fast speed, high accuracy, large measurement range, and strong resistance to light and electrical interference.Classification of Laser Sensors:Lasers can be classified into four types based on the working material.1. Solid-state lasers: Their working material is solid. Common types include ruby lasers, neodymium-doped yttrium aluminum garnet (YAG) lasers, and neodymium glass lasers. They generally have a similar structure, characterized by being small and robust with high power. Neodymium glass lasers are the devices with the highest pulse output power, reaching tens of megawatts.2. Gas lasers: Their working material is gas. There are various gas atomic, ionic, metal vapor, and gas molecular lasers. Common types include carbon dioxide lasers, helium-neon lasers, and carbon monoxide lasers, which resemble ordinary discharge tubes. They are characterized by stable output, good monochromaticity, long lifespan, but lower power and conversion efficiency.3. Liquid lasers: These can be further divided into chelate lasers, inorganic liquid lasers, and organic dye lasers, with the most important being organic dye lasers, which are characterized by their continuously adjustable wavelength.4. Semiconductor lasers: This is a relatively new type of laser, with the most mature being gallium arsenide lasers. They are characterized by high efficiency, small size, light weight, and simple structure, making them suitable for use on airplanes, warships, tanks, and carried by infantry. They can be made into rangefinders and aiming devices. However, they have lower output power, poorer directionality, and are significantly affected by environmental temperature.Working Principle of Laser SensorsWhen a laser sensor operates, a laser emitting diode first aims at the target and emits laser pulses. After reflecting off the target, the laser scatters in all directions.Some of the scattered light returns to the sensor receiver, where it is captured by the optical system and imaged onto an avalanche photodiode. The avalanche photodiode is an optical sensor with internal amplification capability, allowing it to detect extremely weak light signals and convert them into corresponding electrical signals.Commonly used is the laser range sensor, which determines the distance to the target by recording and processing the time taken for the light pulse to travel to the target and back. The laser sensor must measure the transmission time extremely accurately because the speed of light is very fast.For example, the speed of light is approximately 3*10^8 m/s, to achieve a resolution of 1mm, the electronic circuit of the range sensor must be able to distinguish the following extremely short time:0.001m/(3*10^8m/s)=3psDistinguishing a time of 3ps places an extremely high demand on electronic technology, making it very expensive to achieve. However, modern laser range sensors cleverly bypass this obstacle by utilizing a simple statistical principle, the averaging method, to achieve a resolution of 1mm while ensuring response speed.(Source: This text is reproduced from OFWEEK, if there are any inappropriate parts in the text, please feel free to contact us, and we will make timely corrections.)Friendly Reminder: For more industry news, you canclick on the “News Section” in the public account menu under “New Dynamics”,to follow more news here.Scan the QR codes belowto get more information on optoelectronic products
