1. Types of Photodetectors
Photodetectors are sensors that convert light signals into electrical signals and are widely used in various fields, including medical imaging, industrial inspection, environmental monitoring, and communication. Based on their working principles and application requirements, photodetectors can be categorized into several types: photodiodes (PIN/APD), phototransistors, photomultiplier tubes (PMTs), charge-coupled devices (CCD), complementary metal-oxide-semiconductor (CMOS) sensors, InGaAs detectors, thermal detectors (thermocouples, thermistors, microbolometers, etc.), quantum well detectors, avalanche photodiodes, photoelectrochemical detectors, and fiber optic detectors.
2. Photodetectors Used in Fiber Optic Spectrometer
（1）Classified by Wavelength Range:
Silicon-based Detectors: Wavelength range of 200~1100nm, generally including linear or area array CCDs, CMOS sensors, etc.
InGaAs Detectors: Wavelength range of 900~2500nm, generally including linear or area array InGaAs detectors, etc.
（2）Complementary Metal-Oxide-Semiconductor (CMOS)
CMOS image sensors utilize complementary metal-oxide-semiconductor technology. Each pixel integrates a photodiode and an amplifier circuit, converting light signals into electrical signals through the photoelectric effect.
Features of CMOS Sensors:
Low Power Consumption: CMOS sensors integrate amplifiers and readout circuits at each pixel, reducing power consumption.
High Integration: Easy integration with digital logic circuits enables complex image processing functions.
Cost-Effectiveness: Compatible with standard CMOS processes, reducing production costs.
The SR50C and SR75C use high-sensitivity CMOS detectors, ensuring high signal strength even in the ultraviolet range. For more details, please visit the following link: Universal Compact Fiber Spectrometer - JINSP Company Limited (jinsptech.com)
The OCT830E uses a high-speed linear array CMOS primarily for optical coherence tomography imaging, providing users with a high-efficiency signal acquisition speed of 250KHz. For more details, please visit the following link: Best ST830E(ST850E) OCT spectrometer manufacturers and suppliers | JINSP (jinsptech.com)
（3）Charge-Coupled Devices (CCD)
CCD sensors capture images by storing and transferring electrical charges generated by an electric field formed in semiconductor material. When photons hit the photodiode, electron-hole pairs are created; the electrons are stored and transferred along the CCD under the control of clock signals.
Features of CCD Sensors:
High Signal-to-Noise Ratio: Due to their linear charge transfer characteristics, CCDs provide high-resolution, low-noise images.
High Sensitivity: Particularly suitable for low-light environments, capable of capturing faint light signals.
Wide Dynamic Range: Can handle variations from very dark to very bright light.
The SR100B, SR100Z, SR100Q, and SR150S use area array CCD detectors, offering high sensitivity, high resolution, and high signal-to-noise ratio, making them ideal for measuring weak signals. For more details, please visit the following links: High Performance Back-illuminated Fiber Spectrometer - JINSP Company Limited (jinsptech.com) and Scientific Grade CCD Fiber Spectrometer - JINSP Company Limited (jinsptech.com)
Notably, the ST90S and ST100S excel in spectral measurement performance. Their optical design reaches the diffraction limit and, combined with VPH gratings and research-grade CCD detectors, they provide the best choice for measuring extremely weak signals. For more details, please visit the following link: High-Throughput Transmission Fiber Spectrometer - JINSP Company Limited (jinsptech.com)
（4）InGaAs Detectors
InGaAs detectors are infrared detectors based on indium gallium arsenide, particularly suitable for detecting infrared light in the 1-2.5 micron wavelength range. By varying the ratio of indium to gallium, the response wavelength of the detector can be adjusted.
Features of InGaAs Sensors:
Wavelength Selectivity: InGaAs detectors are sensitive to specific infrared wavelengths, making them suitable for spectral analysis.
High Quantum Efficiency: They have a high photoelectric conversion efficiency within specific wavelength ranges.
Wide Operating Temperature Range: Can operate at room temperature without the need for cooling.
The SR50R, SR50N14, SR100N17, SR100N25, and ST50S all use InGaAs detectors to detect near-infrared spectral signals across different bands. For more details, please visit the following link: Near-infrared Fiber Spectrometer - JINSP Company Limited (jinsptech.com)
Post time: Jun-25-2024