Apply online to license this technology
A beam splitter is an optical device that receives an incident light beam and divides it into two components. The first component is propagated from the beam splitter as a transmitted beam. The second component is propagated as a reflected beam, angularly displaced with respect to the transmitted beam.
A conventional beam splitter comprises a cube of optically transparent material that encases a thin layer of semi-reflecting material oriented diagonally across its interior. Approximately half of the light entering one face of the beamsplitter is reflected by the semi-reflecting material through an adjacent face as a reflected light beam. The remaining portion of the light from the incident light is transmitted by the layer of semi-reflecting material through the opposite face as a transmitted light beam.
Beam splitters are used in optical devices such as in scanners, interferometers and back-scattering detectors for measuring reflection from a particle system. One problem associated with conventional cubic beamsplitters is distortion caused by light striking beamsplitter faces at non-perpendicular angles. The transmission through the beamsplitter is refracted according to Fresnel’s Equations. The resulting light beam is parallel to the incident beam but displaced from it. The amount of displacement depends on the angle of incidence and the index of refraction of the optical materials used in the beamsplitter. This distortion can be compensated for, to some extent, by repositioning system components.
Army researchers have developed a beam splitter which is spherical rather than cubic and which can be rotated to alter the angle of incidence. This tuning capability is faster and more precise than the repositioning of optical components under current methods.
- Easier adjustment of the optical material
- Rotation of the sphere can be electronically controlled
- US patent 7,701,638 available for license
- Potential for collaboration with Army researchers