World's first TEA pulsed laser, c 1973.
© Science Museum / Science & Society Picture Library
Close-up detail of the central component of the world's first TEA (Transversely Excited Atmospheric) pulsed laser. This was designed at the Royal Signals and Radar Establishment, Worcester. Standing for 'Light Amplification by Stimulated Emision of Radiation', the laser produces a shaft of intensely coloured (single wavelength) light. The light is also coherent, meaning that all the waves of light are in phase to produce an intense and narrow beam. Laser light is generated within the cylindrical chamber, a space that filled with carbon dioxide gas.