  We explore interstellar light transmission facilitated by gravitational
lensing, focusing on axially-symmetric lensing configurations where the
transmitter, lens, and receiver are nearly aligned. Positioning an optical
transmitter in the lens's focal region, we investigate the caustic formed by a
diffraction-limited annular beam of light emitted by the transmitter. We
analyze the impact of the lens's point spread function (PSF) on the projected
beam's structure, estimate the power delivered to a receiver at interstellar
distances, and assess the major noise sources. We determine detection
sensitivity in both noise- and signal-dominated regimes. Considering realistic
assumptions about the transmitter's performance, we explore signal detection
strategies enhanced by the spatial broadening of the received beam, a result of
the transmitting lens's PSF. Our findings indicate that detecting lensed
optical signals from nearby stars is achievable using established optical
engineering technologies. A network of spatially distributed astronomical
facilities capable of observations in multiple narrow spectral bands will
enhance the search. Our results support the feasibility of interstellar power
transmission via gravitational lensing, directly contributing to ongoing
optical SETI efforts.
