An optical fan for light beams for high-precision optical measurements and optical switching

摘要

The polarization and orbital angular momentum properties of light are ofgreat importance in optical science and technology in the fields of highprecision optical measurements and high capacity and high speed opticalcommunications. Here we show, a totally new method, based on a combination ofthese two properties and using the thermal dispersion and electro-opticaleffect of birefringent crystals, the construction of a simple and robust schemeto rotate a light beam like a fan. Using a computer-based digital imageprocessing technique, we determine the temperature and the thermal dispersiondifference of the crystal with high resolution. We also use the rotationphenomenon to realize thermo-optic and electro-optic switches. The basicoperating principles for measurement and switching processes are presented indetail. The methods developed here will have wide practical applicability invarious fields, including remote sensing, materials science and opticalcommunication networks.