Introduction to photodetectors

A photodetector is a device that converts light signals into electrical signals. In a semiconductor photodetector, the photo-generated carrier excited by the incident photon enters the external circuit under the applied bias voltage and forms a measurable photocurrent. Even at the maximum responsiveness, a pin photodiode can only produce a pair of electron-hole pairs at most, which is a device without internal gain. For greater responsiveness, an avalanche photodiode (apd) can be used.

The amplification effect of apd on photocurrent is based on the ionization collision effect. Under certain conditions, the accelerated electrons and holes can obtain enough energy to collide with the lattice to produce a new pair of electron-hole pairs. This process is a chain reaction, so that the pair of electron-hole pairs generated by light absorption can produce a large number of electron-hole pairs and form a large secondary photocurrent. Therefore, apd has high responsiveness and internal gain, which improves the signal-to-noise ratio of the device. apd will mainly be used in long-distance or smaller optical fiber communication systems with other limitations on the received optical power. At present, many optical device experts are very optimistic about the prospects of apd.

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Rofea independently developed photodetector integrated photodiode and low noise amplifier circuit, while providing a variety of products, for scientific research users Provide quality product customization service, technical support and convenient after-sales service. The current product line includes: analog signal photodetector with amplification, gain adjustable photodetector, high speed photodetector, snow market detector (APD), balance detector, etc.

Feature
Spectral range:320-1000nm、850-1650nm、950-1650nm、1100-1650nm、1480-1620nm
3dBbandwidth:200MHz-50GHz
Optical fiber coupling output2.5Gbps

Modulator type
3dBbandwidt:
200MHz、1GHz、10GHz、20GHz、50GHz

Application
High-speed optical pulse detection
High -speed optical communication
Microwave link
Brillouin optical fiber sensing system


Post time: Jun-21-2023