Double-Beam Spectrophotometers The double-beam spectrophotometer is a device that uses two rather than one beam of light to measure how light is absorbed during spectrophotometry.

Split-Beam Spectrophotometers A split beam spectrophotometer contains a beam splitter which channels light along a reference path and a sample path simultaneously to two separate detectors.

The emergence of imaging schemes capable of overcoming Abbe's diffraction barrier is revolutionizing optical microscopy.

IF a fine beam of homogeneous cathode rays is sent nearly normally through a thin celluloid film (of the order 3 × 106 cm. thick) and then received on a photographic plate 10 cm. away and ...