Information transmission using radial carpet beams

A radial carpet (RC) beam is a new class of beams that is a subfamily of combined half-integer Bessel-like beams, which are a set of solutions for wave equations and introduced recently. In this paper, we propose an indoor optical communication link using RC beams encoding/decoding. By employing spatial light modulators, loaded with radial gratings and fork-shaped gratings as encoders and decoders, respectively, we generate and detect different modes of RC beams as encoding states. In the experiment, we transmit a 2-bit gray-scale image of 50×50 pixels by four different states of RC modes. The system bit error rate (BER) is measured, and a zero BER is achieved after transmitting 2500 modes. We then transmit an 8-bit RGB image of 70×77 pixels by 16 different modes of hexadecimal states to analyze the performance of the communication link in the presence of RC modes with higher RC orders. By defining an optimum threshold value, the maximum improvement of 100% in the fidelity for transmitting 32,340 hexadecimal states in an indoor ideal medium is achieved. The obtained results show acceptable performance for the proposed communication system based on RC beams, especially in the case of lower RC orders.