Infrared (IR) photodetectors (PDs) are crucial for medical imaging, optical communication, security surveillance, remote sensing, and gas identification. In this study, room temperature IR PD was systematically investigated based on two-dimensional b-As0.5P0.5, a relatively unexplored component of b-AsP alloys. High-quality b-As0.5P0.5 flakes were synthesized via Chemical Vapor Transport (CVT) method with precisely controlled conditions. The fabricated b-As0.5P0.5 PD exhibits excellent photoconductivity, high responsivity, and a fast response in the visible and near-infrared (Vis-NIR) band. It achieves a responsivity of ~0.209 A·W−1 and a response time of ~16.6 μs under 1550 nm IR illumination. High-resolution single-pixel point optical imaging and high-speed optical communication were realized by the b-As0.5P0.5 PDs. This study confirms that b-As0.5P0.5 materials are highly promising for advanced IR optoelectronic applications.