The 77806 is a compact, rod mounted beam splitter holder for Oriel^® Fiber Bundles with beam probes. Use it to divide or combine the beams from fiber optics. It includes a fused silica beam splitter coated with an Inconel coating. It has nominal 30%R/30%T from 250 to 2500 nm. Ports at 0, 90, 180 and 270 ° accept up to four beam probes. Angular adjustments on one port provide a small amount of beam alignment. An absorbing cone port plug is included. The bottom of the housing has a 1/4-20 tapped hole for rod mounting; a rod is not included. You can measure relative reflectance (and moderate level fluorescence). Note: this technique eliminates the lens retro reflection that gives a background level when measuring reflectance with a collimated beam from a bifurcated bundle. You can also use the 77806 for dividing or combining small collimated beams, not from beam probes. The clear aperture is 0.5 inch (12.5 mm).