Information transmission via single-pixel coherent detection

Optical wireless communication (OWC) has attracted substantial interest due to its potential for enhanced transmission security and its ability to alleviate spectrum congestion. Here, we propose an information transmission method via single-pixel coherent detection, which realizes coherent OWC with a simple device and low cost. In the method, the information to be transmitted is first encoded into a complex amplitude, which is then divided into a series of sub-complex amplitude using an orthogonal modulation basis. Thus both the amplitude and phase of the complex amplitude can be utilized to transmit the information. Besides, benefiting from the common-path design, the system proposed is stable and simple. The effectiveness of the concept in both free-space and non-line-of-sight (NLOS) transmission has been experimentally verified. Extended experiments at 10-meter distances demonstrate its capability for multi-user transmission. Such a technique can provide a promising approach for short-range OWC applications.