Blue light filter film for visible light communication

Abstract

The invention discloses a blue light filter film for visible light communication, which is structurally characterized in that a wide-pass band interference cutoff filter film, a high reflection film and an antireflection film are arranged on a substrate sequentially. The blue light filter film can greatly reduce noises formed due to a reason that visible illuminating light and background radiation enter a detector. Moreover, since the edge of the blue light filter film for blue light signal penetration and visible illuminating light cutoff is steep and accurate, when the visible illuminating light and near-infrared interference are filtered to an utmost extent, the loss of the blue light signals is minimum, the efficiency and the signal-to-noise ratio of the visible light communication are remarkably improved, and the blue light filter film is very beneficial to the development and the application of fields such as the visible light communication.

Description

technical field [0001] The invention relates to an optical filter film, in particular to a blue light filter film used in visible light communication, which can filter blue light signals for communication from illumination and background light. Background technique [0002] Visible light communication (visible light communication, VLC) is a new optical wireless communication technology developed on the basis of white light LED technology. Compared with traditional radio frequency communication and other optical wireless communications, visible light communication has the advantages of high transmission power, no electromagnetic interference, no bandwidth limitation, and energy saving. It has great development potential and has attracted widespread attention and research. [0003] At present, the light source commonly used in visible light communication is mainly blue LED chip + yellow phosphor to excite white light (spectrum such as figure 1 shown). The blue light LED exci...

AI Technical Summary

Problems solved by technology

[0007] 1) The transmittance of the blue light signal band is not high enough, and there is still room for improvement;

[0008] 2) The out-of-band cut-off is only achieved in the visible band, and the near-infrared band that still has a strong response to the detector has a high transmittance, resulting in insufficient noise and signal-to-noise ratio;

[0009] 3) The boundary between blue light transmission and visible cut-off is not accurate and steep enough, resulting in either too much visible light noise leaking in, or too much blue light signal is filtered out, thereby reducing efficiency and signal-to-noise ratio

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