This is a doublet of 12.5-mm broadband AR-coated fused silica lenses. Placed in front of the cuvette, this assembly focuses an image of end of the source fiber, using a magnification of 1., into the center of a cuvette. Alternatively, this assembly will focus and image of the center of a cuvette onto a collection fiber, using a magnification of 1. Placed at 90 degrees to the excitation, a pair of these lens doublets will efficiently collect fluorescence. Placed on opposite sides of a micro-cuvette (8.5 mm z-height), they will allow you to measure the absorption of small volumes.