Detectors are devices capable of converting various forms of energy or physical quantities into observable or measurable signals. According to the type of physical quantity or energy they detect, detectors can be categorized in many ways. One common method is classification by wavelength. This article will introduce various detectors based on their wavelength classification.
1. Radio Wave Detectors
Radio wave detectors are mainly used to detect radio waves with wavelengths ranging from a few meters to several kilometers. Common examples include:
Antenna: The most commonly used device in radio wave detection, capable of converting radio waves into electrical signals.
Radar: Detects the position and speed of objects by emitting radio waves and receiving their reflections.
2. Microwave Detectors
Microwave detectors operate in the wavelength range of 1 millimeter to 1 meter. Key examples are:
Microwave Diode: A semiconductor device that controls current using the voltage of microwave signals.
Mastson-Stevenson Detector: Measures the speed of microwave propagation in specific media for detection purposes.
3. Infrared Detectors
Infrared detectors cover wavelengths from 700 nanometers to 1 millimeter. Examples include.
Pyroelectric Detector: Detects infrared radiation by measuring the thermal effects it produces on the detector.
Quantum Well Infrared Photodetector (QWIP): Uses electron transitions within quantum well structures induced by infrared radiation for detection.
4. Visible Light Detectors
Visible light detectors operate within the wavelength range of 400 to 700 nanometers. Common types are:
Photodiode: Converts visible light into electrical signals through the photoelectric effect, such as CCD and CMOS sensors.
Photomultiplier Tube (PMT): Amplifies light signals using the photoelectric effect and electron multiplication techniques.
5. Ultraviolet Detectors
Ultraviolet (UV) detectors function within the 10 to 400 nanometer wavelength range. Key examples include:
UV Photodiode: Converts ultraviolet light into electrical signals via the photoelectric effect.
UV Fluorescence Detector: Utilizes ultraviolet light to excite substances to produce fluorescence, which is then detected.
6. X-ray Detectors
X-ray detectors cover wavelengths from 0.01 to 10 nanometers. Examples are:
X-ray Detector: Detects X-rays by measuring their absorption in specific materials.
X-ray Fluorescence Detector: Uses X-rays to excite substances to produce fluorescence, which is then detected.
7. Gamma-ray Detectors
Gamma-ray detectors operate at wavelengths less than 0.01 nanometers. Common examples include:
Scintillation Counter: Detects gamma rays by using them to excite scintillation crystals to produce light signals.
Silicon Detector: Measures the penetration of gamma rays through silicon for detection purposes.
The working principles, sensitivities, and application fields of these detectors vary. Scientists and engineers select appropriate detectors based on specific requirements to achieve precise measurements and monitoring. As technology advances, the performance of detectors continues to improve, broadening their applications across various fields, thereby playing a crucial role in advancing scientific research and promoting technological development.
Post time: Jun-21-2024