Views:0 Author:Site Editor Publish Time: 2021-07-29 Origin:Site
With the continuous development of communication technology in the world, optical fiber communication has gradually become one of the most important communication methods with its advantages of large communication capacity, strong anti-interference ability and fast transmission speed. Relying on optical fiber communication technology, the digital optical terminal began to develop rapidly, and widely used in security, telecommunications, power, industrial control and other fields. As the most important optical terminal in optical fiber communication systems, the optical transmitter has made great progress with the continuous development of communication technology.
Here is the content list:
What are the components of a CATV optical transmitter?
What is the function of the CATV optical transmitter?
What are the categories of CATV optical transmitters?
CATV optical transmitter consists of light source and circuit. It is composed of an input interface, light source, driving circuit, monitoring circuit and control circuit. Its core is a light source and driving circuit. Light source is the key device to realize electro-optic conversion, which determines the performance of optical transmitters to a great extent. In digital communication, the input circuit shapes the input signal, transforms it into a code type suitable for line transmission, and then drives the light source through the driving circuit, or sends it to the light modulator to modulate the continuous light wave output by the light source. In order to stabilize the average output optical power and working temperature, automatic temperature control and power control circuit are usually set.
Optical transmitter is one of the three parts of a digital optical fiber system (optical transmitter, optical fiber cable and optical receiver). Firstly, the HDB3 signal code sent from the multiplexing equipment is transformed into NRZ code, then the NRZ code is coded into the code type required by the transmission performance of the digital optical fiber communication system to be transmitted on the optical cable line, and finally the electrical/optical conversion is carried out to convert the electrical signal into the optical signal and couple it into the optical fiber.
The function of an optical transmitter in a CATV system is to modulate the input RF TV signal and output a stable optical power for transmission in a CATV network. The core part of its work is a distributed feedback laser (DFB), which can select the appropriate output power of the optical transmitter according to the user's needs and be installed in the rack for use.
There is no unified statement about the classification of optical transmitters. Here we will explain and introduce it according to different classification methods.
According to the working frequency, the optical transmitter can be divided into a and B categories: A-type optical transmitter refers to the optical transmitter that transmits 59 PAL-D analog TV signals in the frequency range of 47-550 MHz and digital modulation signals in the frequency range of 550-750 (862) MHz; B-type optical transmitter refers to the optical transmitter that transmits 59 PAL-D analog TV signals in the frequency range of 47-550 MHz and digital modulation signals in the frequency range of 550-750 (862) MHz Optical transmitter is an optical transmitter that transmits 84 PAL-D analog TV signals in the frequency range of 47-750 MHz. According to different modulation modes, optical transmitter can be divided into FM, am and digital modulation. At present, multi-channel AM optical transmitter is widely used, which can be divided into direct modulation and external modulation.
In recent years, with the progress of optical fiber manufacturing technology and the reduction of manufacturing cost, as well as the continuous maturity of optical fiber transmission application technology, especially the wide application of high-power distributed feedback laser and the maturity of optical amplification technology, optical transmitter is more and more widely used in CATV system. Hengchi Electronic Equipment Co., Ltd. has more than 14 years of experience in complex optical fiber and electronic circuits, and all products can stably serve the optical fiber communication engineering and obtain a high evaluation. If you are engaged in CATV optical transmitters industry or have purchase demand, you can consider our high-quality products.