Basically, beam expanders work by using a couple of lenses to make the laser beam wider and, at the same time, cut down on how much it diverges. A beam splitter or beamsplitter is an optical device that splits a beam of light into a transmitted and a reflected beam. It is a crucial part of many optical experimental and measurement systems, such as interferometers, also finding widespread application in fibre optic telecommunications. 📦 For purchasing, use the RP Photonics Buyer's Guide for beam splitters. It provides an expert-curated supplier directory, buyer-focused technical background information, and structured selection criteria to support professional procurement decisions. Contemporary laser beam expander designs are afocal systems that developed from well-established optical telescope fundamentals. In such systems, the object rays.