# Laser-Based Mobile Visible Light Communication System
## 1 Introduction  
Traditional wireless communication technology has been widely used in people's daily life, and the demand for wireless communication technology has grown exponentially, underscoring its importance in the modern world [1]. However, as demands for higher data rates, lower latency, increased capacity, and multiple connections grow, wireless communication technologies face significant bottlenecks and challenges. The emergence of visible light communication (VLC) promises a solution to these issues [2, 3]. Unlike radio frequency communications, VLC offers abundant spectrum resources, superior interference resistance, and enhanced security. Importantly, VLC can utilize existing lighting infrastructure to provide dual functionality in illumination and communication, serving as an effective supplement to existing wireless networks, known as light fidelity (LiFi) [4, 5]. Research on VLC over the past decades has made significant progress, achieving breakthroughs in communication rates through the optimization of transmitter and receiver devices, advancements in modulation and equalization algorithms, and the application of multiple-input multiple-output (MIMO) technology [6, 7, 8, 9, 10]. In laser-based VLC systems, laser diodes (LDs) present a promising avenue due to their high modulation bandwidth and output power, indicating potential for high-speed and long-distance communications [11, 12]. However, the narrow beam and concentrated spot of LDs necessitate precise alignment for high-capacity transmission, which severely limits the mobility of communication systems. Mobility, a fundamental advantage of wireless services, provides users with flexibility and convenience, enabling connections while on the move. In the age of mobile internet, there is a universal expectation for ubiquitouscommunication capabilities, requiring communication systems that accommodate mobility. Actually, the vast majority of envisioned applications for VLC require implementation in mobile scenarios. For instance, smart homes, smart cities, and factory floor communication, among others. In short-range scenarios, the necessity of mobile VLC is evident in electromagnetic-sensitive environments such as hospitals or where current mobile technologies struggle to provide coverage. For instance, on trains or airplanes, VLC technology enables passengers to quickly establish ad hoc networks for information exchange and local social networking applications. In emergency situations, emergency lights or exit signs can communicate with victims' portable devices, providing the shortest paths to safety exits. In addition, the study of mobile VLC is also important for underwater communications, especially in the presence of turbulence [13]. Given that most envisioned applications of VLC operate in mobile scenarios, there is an urgent need to explore mobile VLC systems. We envisioned an indoor LiFi application scenario for mobile VLC, as depicted in Figure 1. People's mobile phones, computers, and other mobile devices can wirelessly connect through indoor lighting and connect to control electronic devices such as printers and projectors. To ensure the effective maintenance of a VLC link during mobility, it is first imperative to guarantee that the light source not only illuminates within a certain range, but can also support communication. Thus, the study of wide field-of-view (FOV) VLC holds significant importance. Lasers, characterized by their narrow divergence angles, have traditionally been utilized in point-to-point communications. Consequently, there is a need to expand the illumination range of laser beams and explore large-angle receiving solutions. Some researchers have delved into this area in recent years. [PERSON] et al. innovatively extended the coverage range of a light source to a full angle of 76\({}^{\circ}\) through the integration of Micro-Electro-Mechanical Systems' steering mirrors and angle amplification modules. Laser-based white light consists of red, green, blue, and violet LDs four color multiplexing.