Optical wireless communication (OWC) or free space optical (FSO) communication systems transmit information through the atmosphere using light beams in the visible or near-infrared (NIR) spectrum. Since the radio frequency spectrum is overwhelmed and unable to meet the key performance indicators of FSO communication, high data rates can be provided by communicating over the visible or NIR spectrum. In this study, we have proposed a complementary metal-oxide semiconductor (CMOS) compatible all-silicon spin-encoded metalens that offers several key advantages for FSO communication applications. Firstly, it can be flawlessly merged with CMOS electronic devices, enabling the development of miniature-sized and cost-effective FSO communication systems. Secondly, due to silicon's high refractive index and all-silicon design, the proposed metalens offer effective light focusing and manipulation. Moreover, silicon is opted for because it is a transparent material for the visible and NIR spectrum, hence making it an appropriate choice for manufacturing a device for the application of efficient FSO communication. Furthermore, the all-silicon design of metalens makes it possible to be seamlessly integrated with other silicon-based photonic elements, including waveguides, modulators, and detectors. Our proposed CMOS, compatible with all silicon spin-encoded metalens, is an ultra-compact design that is capable of providing dual focal points simultaneously and transmitting different messages to different users at run time. We have designed and simulated a 60 µm × 60 µm all-silicon spin-encoded metalens and acquired two focal points by shining the linearly polarized light. Metalens inclusion within the FSO communication system opens new avenues for next-generation OWC, offering better focusing of light beams, enhancing the signal intensity, and escalating the overall communication range.
|