Receiving antenna of optical communication system

Abstract

The character of the optical receiving antenna is that it also contains a detector and a light cone and an immersion lens. The immersion lens is positioned at the small end of the light cone, and thedetector is positioned at the back surface of the immersion lens. The large end of the optical cone is located near the focal plane of the optical system so as to extend receive aperture, increase the light energy entered to the system. Large aperture makes the detector insensitivity to the focal point. Thus, the optical path is easy to be adjusted, increasing the capability of anti vibration. The immersion lens raises the receiving visual angle of the detector, making the small detector receive optical signal from larger area of visual field so as to obtain high S / N ratio. Moreover, the immersion lens shortens the length of FSO system making structure compact.

Description

1. Technical field [0001] The invention relates to an optical communication system, in particular to a receiving antenna which adopts an auxiliary optical system to improve the receiving performance of optical signals, which is suitable for but not limited to a free space optical communication system (FSO). 2. Background technology [0002] Optical fiber communication and wireless communication are currently popular technologies, and the free space optical communication system is the product of the combination of the two. It has some advantages of optical fiber communication and some advantages of wireless communication. Compared with these two technologies, its unique features are as follows: [0003] Compared with radio communication (such as microwave): it does not occupy valuable radio frequency resources; it has good electromagnetic compatibility, strong anti-electromagnetic interference ability, and good confidentiality; it has large information capacity; it is small i...

AI Technical Summary

Problems solved by technology

In short, the problems of direct reception with optical signal detectors are: 1. When the receiving area of ​​the detector is smaller than the light spot, a large amount of light energy will be lost, resulting in shorter system transmission distance and lower signal-to-noise ratio, which seriously affects system performance; The faster the speed, the more obvious the impact

2. The coordination and adjustment of the detector and the receiving optical system is extremely difficult. Even after the adjustment and installation are completed, the detector will deviate from the position of the beam waist under the influence of vibration, which will seriously damage the system performance.

3. The influence of the receiving effect at the detector end is far greater than that of the optical antenna at the sending end, the optical system at the receiving end, and the laser. In extreme cases, the efforts of the current FSO manufacturers in the work described below will be in vain.

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