Wadsworth constant deviation system
In optics, Wadsworth's constant-deviation prism-mirror system (or Wadsworth constant deviation mounting) is a method to arrange a prism or diffraction grating and a mirror on a turntable to ensure that rays of light emerge in a fixed direction.[1] Typically, light entering via a slit is directed into the prism by a lens. A particular wavelength can be chosen for analysis by setting the angle of the prism, and hence the part of the spectrum that exits by a mirror and lens combination. Rotating the prism through its entire range of motion enables the entire spectrum to be analyzed.[2]
An analytical proof for the arrangement was given by Wadsworth,[1] followed almost three decades later with a geometric proof by Gibbs and Collins.[3] It is considered a "classic" prism configuration being versatile on its own or in combination with many other configuration and instrumentation combinations.[4]
Among many other applications, Wadsworth constant deviation mountings have been used to study light emissions from excited metal atoms,[5] and to study the light needs of plants in future space missions.[2]
References
- ↑ 1.0 1.1 Wadsworth (1894). Astronomy and Astro Physics, Vol. 13, p. 835.
- ↑ 2.0 2.1 Nevell, G.E. Jr., et al. (1989). Design and Implementation of Sensor Systems for Control of a Closed-Loop Life Support System. NASA-CR-186675
- ↑ R. C. Gibbs; J.R. Collins (1922). "Geometrical Proof for the Wadsworth Constant Deviation System". Phys. Rev. 19, 381.
- ↑ George J . Zissis (1995). "Dispersive prisms and gratings" (pdf) in Michael Bass et al. (eds.) Handbook of Optics. Vol. 2, Ch. 5. McGraw Hill.
- ↑ H Lund and L Ward (1952). Proc. Phys. Soc. B Vol. 65, no. 535