What is optical receiver? An optical receiver is a device that converts optical signals transmitted by optical fibers into electrical signals in communications. This article provides a more comprehensive introduction to what is optical receiver and the consist of optical receiver, how optical receiver works with fiber optic, and how optical receiver works with optical transmitter.

What is optical receiver?

The optical receiver is one of the important devices in the catv optical fiber communication system.
The main function of the optical receiver is to receive the optical signal transmitted through the optical fiber and convert it into the electrical signal in CATV communication system. The optical receiver can also perform associated signal processing or amplify the signal.
Optical receivers are mainly used in CATV systems, broadband access networks and large-scale optical fiber communication networks.

Why does an optical receiver consist of a photodetector and a transimpedance amplifier? 

The consist of optical receiver

Optical receivers usually consist of photodetectors and transimpedance amplifiers. This has to do with how optical receivers work.

Photodetector

The photodeterctor is the main component of the optical receiver.

There are photodetectors made of many materials, Silicon, for example, is the most commonly used material for making photodetectors. Photoelectric ceramic materials, which have high density and high mechanical strength. They are often used in the manufacture of infrared photodetectors. Semiconductor materials, photodetectors made of this material have high sensitivity and fast response.

The main function of photodetectors in optical receivers is to convert optical signals into electrical signals.

This process mainly relies on the photoelectric effect.

photodetector Photoelectric effect

The basic steps for converting optical signals into electrical signals are:

1.Photon absorption

When light strikes the light-sensitive material of a photodetector, the photons interact with the atoms in the material.

2.Electronic excitation

After the photon is absorbed by the material, the electrons in the material jump from a low energy level to a high energy level.

3.Form electron-hole pairs

When an electron is excited into the conduction band, a hole is left where the electron originally was.

4.Carrier Migration

Under the action of the internal electric field of the photodetector, the excited electrons and holes move in opposite directions, forming an electric current. This current caused by photogenerated carriers is called photocurrent.

5.Current Output

The photocurrent passes through the circuit structure of the photodetector, is amplified and conditioned. Then it is finally converted into a usable electrical signal output.

Transimpedance amplifier

Transimpedance amplifiers are also available in many materials. Such as semiconductors, silicon and insulating materials. Insulating materials are often used to isolate different circuit parts.

Semiconductors and silicon are used to make semiconductor field-effect transistors (MOSFETs), a device commonly used in transimpedance amplifiers.

The transimpedance amplifier is located at the forefront of the optical receiver. It is an electronic amplifier. The main function of the transimpedance amplifier is to convert the output current (signal) converted by the photodetector into a voltage signal. Then provides impedance matching during conversion.

Transimpedance amplifier work diagram

The transimpedance amplifier provides the necessary electrical signal form for subsequent signal processing. The process of converting output current into a voltage signal mainly relies on Ohm’s law and negative feedback mechanisms.

Use of Optical Receivers and Optical Fiber, Optical Receiver and Optical Transmitter

Optical receivers are often used with communication equipment such as optical fiber and optical transmitters.

Optical receivers are used together with optic fibers

Baudcom 6core Direct Buried Optical Fiber Cable

First, the end of the optical fiber needs to be properly treated, such as grinding and cleaning. This ensures that the optical signal is efficiently coupled to the photodetector of the photoreceiver.

Second, the connection between the optical receiver and the optical fiber requires precise alignment. This can reduces the loss of optical signals.

The connection between the optical receiver and the optical fiber can be a point-to-point connection, a bus connection or a ring connection.

Finally, the size of the photodetector inside the optical receiver needs to be compatible with the size of the fiber core.

If you need your optical receiver to be used with optical fiber, you can consult Baudcom. Baudcom can provide you with professional optical fiber and optical receiver solutions.

 

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