Application of Coated Filter in Optical Communication

1. The role of the filter.

The optical filter is one of the most important components in optical communications, and its manufacturing technology is also very complex, with the characteristics of a long coating cycle, multiple processing and testing procedures, high product accuracy standards, and small cutting size. With the rapid development of optical communications, people are paying more and more attention to the research and development of optical filters. At present, optical filters are developing in the direction of flexible design, light weight, and stable signal. 

2. Wavelength division multiplexing filter

The wavelength division multiplexing filter is a commonly used filter in optical communications. Among them, according to the difference in channel spacing, the wavelength division multiplexing filter can be divided into a wide wavelength division multiplexing filter, a coarse wavelength division multiplexing filter and a dense wavelength division multiplexing filter to form a wavelength division multiplexing filter. There are two main technologies for multiplexing filters, namely multiplexing technology and demultiplexing technology. In contrast, demultiplexing technology has higher requirements on the material of the filter. 

In optical communication equipment, wavelength division multiplexing filters are mainly used in wavelength switches and all-optical add-on/off speech systems. At the same time, wavelength division multiplexing filters can also be the same as AWG (ie, arrayed waveguide grating). Used together, it can reduce the channel crosstalk phenomenon of the arrayed waveguide grating. 

The wavelength division multiplexing filter is designed with a narrow passband, small ripple, and low filter loss. Therefore, the specific stability is higher. It can achieve more than one hundred layers of coating on the basic filter, but at the same time, this Coating technology has a certain degree of difficulty, and there will be higher standards for the accuracy of filter packaging.