Performance Investigation on Hemispherical Lens used in Photodetector for Visible Light Communications

Visible light communication (VLC) has attracted a lot of attentions. However, there are still some difficult issues need to be solved for practical applications, such as the small active area of the PD. The transmission distance and incident angle greatly affect the stability of VLC system. In this work, the influence of transmission distance, incident light angle and received optical power of receiver on VLC system has been investigated. In order to improve the performance of the receiver, series of hemispherical lenses for photodetector were analyzed. By fabricating suitable hemispherical lens, the signal to noise ratio (SNR) was measured under different condition, and the experiment results showed that the suitable hemispherical lens can well improve the communication performance of the VLC system.