as a whole onto another table without the need to realign the components on the breadboard. Similarly, custom-built optical devices are assembled and aligned on breadboards, which are then enclosed in a case and shipped to the customer. Rails and benches An optical bench or optical rail is a simpler piece of hardware that provides a linear (or sometimes curved) track along which to mount optical elements. They are often used for simple experiments, especially for classroom demonstrations. Such rails are typically made of steel and designed to be very stiff, with features that allow holders for optical components to be bolted down and easily shifted along the length of the rail. Rails are common in laser assemblies where the beam path travels on a single axis. A more sophisticated example is the silicon carbide ceramic toroidal optical bench in the Gaia spacecraft (illustrated), which supports several optical instruments. See also Optical cage system References External links Optical table simulator Fundamentals of Vibration Isolation for Optical Tables Laboratory equipment Tables (furniture) Table, optical