— Build domestic professional —

Audio-optic technology professional platform

news

09

2022

-

12

How to select the appropriate photodetector?


According to the working principle and structure, photodetectors are generally divided into photoelectric detectors and thermoelectric detectors. Photoelectric detectors include vacuum photoelectric devices (photomultiplier tubes, etc.) and solid photoelectric detectors (photodiodes, photoconductive detectors, CCD, etc.).
● Photomultiplier tubes (PMT)
Photomultiplier tube (PMT) is a kind of light detection device with extremely high sensitivity, and has the characteristics of fast response, low noise, large area cathode (photosensitive surface), etc.
● Photodiode
The working principle of the photodiode is mainly based on the photovoltaic effect. Photovoltaic effect is the effect that semiconductor materials produce electromotive force on PN junction after absorbing light energy.
● Photoconductive detector
The photoconductive detector is a kind of light detection device made of the photoconductive effect of semiconductor materials. The so-called photoconductivity effect refers to a physical phenomenon that changes the conductivity of the irradiated material caused by radiation.
In the photoelectric test system, various detectors need to be selected according to the actual needs, especially the following aspects:
1. The actual spectrum measurement range, which is the first problem to pay attention to when selecting optical detectors;
2. The photomultiplier tube is a highly sensitive detector with a limited wavelength range (usually up to 900 nm, some models can get more than 1000 nm, but the price is usually very expensive), and requires a high voltage power supply with high stability when used;
3. Photovoltaic detectors have the characteristics of fast response and high sensitivity. Generally, phase-locked amplifiers are not required for use. When detecting weak signals, phase-locked amplifiers can be selected to improve the signal-to-noise ratio;
4. The photoconductive detector has a slow response. When it is used, the signal light is required to be * * * modulated, and it needs to be matched with a phase-locked amplifier to detect the signal. At the same time, attention should be paid to the selection of modulation frequency;
5. When selecting detectors, it is particularly necessary to pay attention to the selection of matching preamplifiers in order to maximize the detection efficiency of detectors;
6. When selecting TE refrigeration type detector, pay attention to the selection of corresponding temperature controller. The detector, temperature controller and preamplifier should be selected separately according to needs;
7. Infrared detectors usually need refrigeration and use with phase-locked amplifiers.

How to select the appropriate photodetector?

According to the working principle and structure, photodetectors are generally divided into photoelectric detectors and thermoelectric detectors. Photoelectric detectors include vacuum photoelectric devices (photomultiplier tubes, etc.) and solid photoelectric detectors (photodiodes, photoconductive detectors, CCD, etc.).

2022-12-09


Basic principle of acoustooptic modulator

Acousto-optic modulator is a device that can control the power, frequency or spatial direction of laser beam by using electronic driving signal. It uses the acoustooptic effect, that is, the refractive index is changed by the mechanical oscillation pressure of the sound wave.

2022-12-09


The 15th China International Semiconductor Lighting Forum and 2018 International Third Generation Semiconductor Forum opened in Shenzhen

In the afternoon of October 23, 2018, the 15th China International Semiconductor Lighting Forum and 2018 International Third Generation Semiconductor Forum Opening Conference was held in Shenzhen Convention and Exhibition Center; With the theme of "creating core, gathering intelligence and sharing ecology", the conference attracted the active participation of experts and scholars from domestic and overseas semiconductor lighting, the third generation of semiconductors and related fields, enterprise leaders, industry organization leaders and relevant government officials, and jointly discussed the development of the industry.

2018-10-25


Shangmao Technology invites you to participate in the Shanghai Optical Expo in Munich

On July 3-5, 2020, Shangmao Technology will display high-performance optical fiber acoustooptic modulator, acoustooptic adjustable filter, acoustooptic driver and other acoustooptic products at the 8.1E432 booth in the 8.1 Pavilion, as well as optical passive devices such as ring and isolator for the first time. We look forward to your visit and negotiation!

2020-06-18


Notice of Holiday in 2020 Rat Year

Notice of Holiday in 2020 Rat Year

2020-01-19


Thank you for your interest in our product series. If you need more product information or personalized customization, please leave us a message and we will reply to you as soon as possible!