Optical detection of the Casimir force between macroscopic objects

Abstract

We report the optical detection of mechanical deformation of a macroscopic object induced by the Casimir force. An adaptive holographic interferometer based on a photorefractive BaTiO3:Co crystal was used to measure periodical nonlinear deformations of a thin pellicle caused by an oscillating Casimir force. A reasonable agreement between the experimental and calculated values of the first and second harmonics of the Casimir force oscillations has been obtained.

10.1007/s11451-008-2002-3

“…This paper is devoted to a theoretical calculation of the Casimir force for plates exhibiting a frequency-dependent permittivity ε ( ω ) and having a finite thickness L . It is under these conditions that the experiments were carried out in [11,12]. The calculation performed in the present work has demonstrated that the final result depends on two dimensionless parameters, i.e., Z / L and κ p Z , where κ p = ω p / c is the wave vector related to the plasma wavelength λ p through the standard relationship λ p = 2 π / κ p .…”

“…The measurements carried out in [11,12] have demonstrated that the experimental value of the Casimir force is at least one order of magnitude smaller than the value predicted from the theory for the geometry used in the experiment (namely, the interaction of flat and spherical metal surfaces). One of the reason for weakening the Casimir force is well known and associated with the presence of plasma oscillations in a semiconductor.…”

“…Then, according to relationship (15), we have where κ p = ω p /c is the wave vector of the plasma wave (see above). In this notation, according to relationship (14), we have , (17) which is independent of p. As a result, the contribution from the TE modes to the Casimir force according to relationship (11) takes the form (18) where P 0 is the limiting pressure of the Casimir force according to relationship (1), and…”

“…A detailed description of these experiments and relevant references can be found in reviews [3,10]. A new method has recently been proposed to measure the Casimir force with the use of dynamic holography [11,12]. However, in all these experimental methods, there arise two principal problems, namely, the problem of determination of the absolute value of the Casimir force and the problem of determination of the absolute value of the gap Z between the plates.…”

“…In [11,12], the absolute value of the Casimir force was calibrated against the pressure of laser radiation; i.e., the laser radiation was used as a natural standard of pressure. The measurements carried out in [11,12] have demonstrated that the experimental value of the Casimir force is at least one order of magnitude smaller than the value predicted from the theory for the geometry used in the experiment (namely, the interaction of flat and spherical metal surfaces).…”