In some embodiments, a 1.times.N optical switch includes: a plurality of co-planar, parallel output optical fiber collimators oriented to receive light substantially perpendicular to a longitudinal direction; and a plurality of switching units each corresponding to an output collimator. Each switching unit includes a rhomboid switching prism movable between a first position and a second position, and a fixed right-angle reflector facing the output collimator. When the switching prism is in the first position, the switching prism receives a longitudinal light beam and directs the light beam to the reflector for transmission to the output collimator. When the switching prism is in the second position, the switching prism is situated out of a path of the light beam. The described configurations may be optically reversed to yield N.times.1 switches.