Fiber optic bundle array wide field-of-view optical receiver for free space optical communications

Abstract

We propose a design for a free space optical communications (FSOC) receiver terminal that offers an improved field of view (FOV) in comparison to conventional FSOC receivers. The design utilizes a microlens to couple the incident optical signal into an individual fiber in a bundle routed to remote optical detectors. Each fiber in the bundle collects power from a solid angle of space; utilizing multiple fibers enhances the total FOV of the receiver over typical single-fiber designs. The microlens-to-fiber-bundle design is scalable and modular and can be replicated in an array to increase aperture size. The microlens is moved laterally with a piezoelectric transducer to optimize power coupling into a given fiber core in the bundle as the source appears to move due to relative motion between the transmitter and receiver. The optimum position of the lens array is determined via a feedback loop whose input is derived from a position sensing detector behind another lens. Light coupled into like fibers in each array cell is optically combined (in fiber) before illuminating discrete detectors.

Space Optical Links for Communication Networks

“…A fiber bundle can collect more power and combine the signals optically or electrically, following the same approach than before. Such approaches have been developed to increase the FOV of lasercom systems [96]. The same idea can be though by using a multimode fiber.…”

Coupling Efficiency of a Partially Coherent Radially Polarized Vortex Beam into a Single-Mode Fiber

“…One can improve the signal-to-noise ratio and save energy through increasing the coupled light beam. During the past decades, many theoretical methods and experimental techniques were used to improve the coupling efficiency, such as a fiber array [11], cylindrical glass fiber [12], wedge-shaped fiber endface [13], combination lens [14], chemically etched self-centered diffracting element [15], and a microlens [16].…”

Wavelength dependence of a fiber-bundle based FSO link

“…For longer distances and outdoor environments, the presence of atmospheric turbulence and weather can produce signal fade or loss for traditional FSO designs. Solutions that increase the transmitter power, the collecting area of the receiver, or the number of spatially diverse transmitter-receiver pairs [1][2][3][4][5][6][7][8][9] have limited utility in the mobile scenario by practical limits on the size, weight, and power consumption (SWaP) of the mobile transceivers that are imposed by the moving platform's capabilities. While several design solutions have been proposed to address these issues, there remains room for new FSO system designs to further improve upon the performance of mobile FSO.…”