Abstract
We report the implementation of a highly sensitive tunable beam displacer based on the concept of weak value amplification, that allows to displace the centroid of a Gaussian beam a distance much smaller than its beam width without the need to deflect the direction of propagation of the input beam with movable optical elements. The beam's centroid position can be displaced by controlling the linear polarization of the output beam, and the dependence between the centroid's position and the angle of polarization is linear.
Highlights
A polarization beam displacer (BD) is a device that splits an input polarized beam into two spatially separated beams that propagate parallel with orthogonal polarizations
We report the implementation of a highly sensitive beam displacer based on the concept of weak value amplification that allows to displace the centroid of a Gaussian beam a distance much smaller than its beam width without the need to use movable optical elements
Close to β = 45◦ the centroid position of the output beam varies almost linearly with respect to the postselection angle over the range −∆x ≤ x ≤ +∆x [see Fig. 3 (a)], and the insertion loss is small for the same interval [see Fig. 3 (b)], making the weak value amplification scheme described in Fig. 1 (a) suitable for implementing a low-loss highly sensitive tunable beam displacer where the spatial shift is controlled by projection into a given polarization state, with no movable optical elements
Summary
A polarization beam displacer (BD) is a device that splits an input polarized beam into two spatially separated beams that propagate parallel with orthogonal polarizations. To the best of our knowledge, a scan of the position of a single beam can be implemented either by using an arrange of moving mirrors [3, 4], a plane-parallel plate or a tunable beam displacer (TBD) [5]. When the angle is different from zero, the input beam splits into two parallel propagating beams with orthogonal polarizations separated by a distance proportional to the rotation angle. For all the cases mentioned above the beam shift results from the mechanical rotation of an optical element This condition imposes a technical limitation on the sensitivity of the beam displacer since it directly relates to which sensitivity we can achieve when performing the rotation. In a plane-parallel plate displacer one can obtain a typical beam shift of ≈ 12.5 μm/deg, where the proportionality factor depends on the thickness of the plate and its index of refraction. We make use of the concept of weak value amplification [9, 10], that allows to convert two beams with orthogonal polarizations that slightly overlap in space into a single beam whose center can be tuned by only modifying the linear polarization of the output beam
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
