Panoramic laser communication optical systems for low Earth orbit satellite networking.

Laser communication, which is known for its high data rate and large capacity, is a promising solution for future large-scale satellite constellation networking. However, the limited field of view (FOV) of current communication terminals makes establishing inter-satellite links challenging. This paper presents a wide-field optical system for laser communication that addresses the challenge of the limited field of view (FOV) in current satellite terminals. The system links the FOV to the outgoing light rays using vector reflection laws and ray tracing. The aperture extension method gradually enlarges the system's transmit and receive apertures to meet the inter-satellite communication needs. The optical head was designed by fitting a freeform surface contour based on the data points and XY polynomial coefficients. After optimization, the system achieved an FOV range of ±30∘ to ±70∘ and supported laser communication over 1200 km, with divergence angles meeting the space communication requirements. Comparative analysis shows that freeform surfaces outperform non-spherical designs, offering reduced distortion and an improved modulation transfer function (MTF), and freeform surfaces reduce the beam spread of the system by about 50% and extend the communication range by about 450 km. These results demonstrate the potential of freeform optics for scalable and high-performance satellite communications, providing a theoretical foundation for future satellite networks.