A microlens 30 is formed on the outer surface of an optical fiber 20 having an in-fiber Bragg grating 24 (FBG) formed in the core 21, 36 thereof, to focus light diffracted by the FBG onto other fibers or optical devices, or to focus light received at the fiber onto the FBG. Various single- and multi-microlens configurations of one or more fibers perform a variety of functions such as signal coupling, multiplexing, signal splitting, spectrography, tapped delay, timed-delay phase adjusting, circulating storage, and so forth. The microlenses may employ angle-increasing prisms and may comprise Fresnel lenses.