The present disclosure is directed toward optical elements, such as sample cuvettes, lenses, prisms, and the like, whose transmissivity is increased by the addition of a geometric anti-reflection layer disposed on at least one surface of the optical element, where the geometric anti-reflection layer includes a plurality of geometric features that collectively reduce the reflectivity of the interface between the surface and another medium. As a result, more of an optical signal incident on the surface passes through the interface. In some embodiments, every surface through which an optical signal passes includes a geometric anti-reflection layer. Due to the increased transmissivity of the optical element, in some embodiments, the use of low-cost, high-refractive-index materials, such as conventional silicon, is enabled.