© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:1806.08980 · Physical Review A

Interferometric and Uhlmann phases of mixed polarization states

Alexei D. Kiselev, Vladimir V. Kesaev

Published Sep 13, 2018• 5 citations

Abstract

In our investigation into the effects of the degree of polarization in modulation of partially polarized light, we assume general settings of the interferometry of partially polarized light waves and perform theoretical analysis of the geometric phases: the Uhlmann phase and the interferometric phase. We introduce the relative Uhlmann phase determined by the Uhlmann holonomies of interfering beams and show that the interferometric phase generalized to the case of nonunitary evolution can, similar to the Uhlmann phase, be cast into the holonomy defined form. By using the technique based on a two-arm Mach-Zehnder interferometer, two different dynamical regimes of light modulation are experimentally studied: (a) modulation of the input light by the rotating quarter-wave plate (QWP), and (b) modulation of the testing beam by a birefringent plate with electrically controlled anisotropy represented by the deformed-helix ferroelectric liquid-crystal (DHFLC) cell. In the setup with the rotating QWP, the interferometric phase is found to be equal to the relative Uhlmann phase. Experimental and theoretical results being in excellent agreement show both that this phase is an oscillating function of the QWP angle and increases with the degree of polarization. For modulation by the DHFLC cell, the data derived from our electro-optic measurements are fitted using the theory of the orientational Kerr effect in FLCs. This theory in combination with the results of fitting is used to evaluate electric field dependencies of the interferometric and the Uhlmann phases.

DOI: 10.1103/physreva.98.033816

Related papers

Coherence and polarization control by means of 90°-twist nematic liquid-crystal spatial light modulators (NLC-SLM)

Carolina Rickenstorff-Parrao, Elías Flores, Andrey S. Ostrovsky

The coherence and polarization degrees of an electromagnetic beam are modulated through two 90°-twist nematic liquid-crystal spatial light modulators placed at the opposite arms of a Mach-Zehnder interferometer. Statistical properties of the secondary source are modified applying random signals to the 90°-twist NLC-SLMs working in the phase mode. Experimental results are obtained using the commercial device LC2002 Holoeye.

Frontiers in Optics•Jan 1, 2011•2 citations

Pancharatnam’s connection and geometric phase of partially polarized light

Kaisa Rantaeskola, Kimmo Saastamoinen, Andreas Norrman +3 more

We extend the concepts of Pancharatnam’s connection and phase difference of optical beams to cover random, stationary, partially polarized quasimonochromatic light. The geometric and dynamic structures of the phase are assessed within the framework of classical statistical polarization theory when the beam undergoes a cyclic, unitary polarization-state evolution. The existence of the two phase types is confirmed experimentally by conducting an interferometric measurement where the phase changes are found from the variations in the position of an intensity fringe pattern. The formalism also leads to a definition of the geometric phase for partially polarized beams, which is consistent with the results on mixed (qubit) quantum states.

Optica•Nov 26, 2024•1 citation

Tunable decoherence of quantum polarization states via birefringence-frequency coupling using liquid crystal

GYA PRASAD, Rajneesh Joshi

We theoretically investigate a novel mechanism for controlling the quantum degree of polarization of single- and multi-photon light fields through the combined effects of birefringence and dispersion in optical media. While birefringence alone introduces a unitary phase shift between horizontal (H) and vertical (V) polarization modes, the inclusion of dispersion produces frequency-dependent effects that couple polarization with spectral degrees of freedom, thereby inducing decoherence and transforming the quantum state into a mixed state. By employing an electro-optically controlled nematic liquid crystal as the birefringent medium, this decoherence process can be harnessed to achieve tunable control of the quantum degree of polarization. We model this voltage-dependent tunability theoretically and propose methods for experimental verification.

•Oct 8, 2025•0 citations

Tunable decoherence of quantum polarization states via birefringence-frequency coupling using liquid crystal

GYA PRASAD, Rajneesh Joshi

We theoretically investigate a novel mechanism for controlling the quantum degree of polarization of single- and multi-photon light fields through the combined effects of birefringence and dispersion in optical media. While birefringence alone introduces a unitary phase shift between horizontal (H) and vertical (V) polarization modes, the inclusion of dispersion produces frequency-dependent effects that couple polarization with spectral degrees of freedom, thereby inducing decoherence and transforming the quantum state into a mixed state. By employing an electro-optically controlled nematic liquid crystal as the birefringent medium, this decoherence process can be harnessed to achieve tunable control of the quantum degree of polarization. We model this voltage-dependent tunability theoretically and propose methods for experimental verification.

•Oct 8, 2025•0 citations

Effect of Light Polarization on Hanbury Brown-Twiss Experiment

Dongshi Guan, Jun Xiong, Su-Heng Zhang +2 more

This article studies,both theoretically and experimentally,how the degree of polarization and the polarization state of polarized light affect the normalized second order correlation g(2) in Hanbury Brown-Twiss experiment.In the experiment,the plane polarized light is changed into elliptically polarized light by passing it through a 1/4 wave plate.By rotating the wave plate,the polarization state of light can be changed.Two beams of light with mutually perpendicular vibration direction,same propagation direction and random phase difference are compounded into a partly polarized light.By adjusting the intensity of one beam of the light,the degree of polarization can be changed.It is shown that for polarized light,the state of polarization causes no change in g(2).On the other hand,for light with different degrees of polarization(P),g(2) is a quadratic function of P.For natural light,P=0,and the maximum g(2) in theory is 1.5;for polarized light,P=1,and the maximum g(2) in theory is 2.

Acta Sinica Quantum Optica•Jan 1, 2009•0 citations

Geometric phases in two-photon interference experiments

Jurgen Brendel, Wolfgang Dultz, W. Martienssen

Photon pairs produced by type-I and type-II parametric down-conversion are passed through a Michelson interferometer. Two quarter-wave plates in one arm of the interferometer allow variation of the polarization state of the photons. We investigate experimentally the geometric phase or Pancharatnam phase acquired by single photons and photon pairs dependent on the solid angle that is subtended by the circuit that represents the varying state of polarization on the Poincar\'e sphere. It is found that the geometric phase acquired by the pair depends on the initial polarization state of the two photons. If both photons are in equal states of linear polarization, we observe a doubling of the geometric phase compared to single photons; in the case of orthogonal states of linear polarization, the geometric phase is completely canceled. Our results show the role of Pancharatnam's phase in nonclassical two-photon interference phenomena and the interplay between the geometric phase and the dynamical phase in these phenomena.

Physical Review A•Oct 1, 1995•44 citations

In our investigation into the effects of the degree of polarization in modulation of partially polarized light, we assume general settings of the interferometry of partially polarized light waves and perform theoretical analysis of the geometric phases: the Uhlmann phase and the interferometric phase. We introduce the relative Uhlmann phase determined by the Uhlmann holonomies of interfering beams and show that the interferometric phase generalized to the case of nonunitary evolution can, similar to the Uhlmann phase, be cast into the holonomy defined form. By using the technique based on a two-arm Mach-Zehnder interferometer, two different dynamical regimes of light modulation are experimentally studied: (a) modulation of the input light by the rotating quarter-wave plate (QWP), and (b) modulation of the testing beam by a birefringent plate with electrically controlled anisotropy represented by the deformed-helix ferroelectric liquid-crystal (DHFLC) cell. In the setup with the rotating QWP, the interferometric phase is found to be equal to the relative Uhlmann phase. Experimental and theoretical results being in excellent agreement show both that this phase is an oscillating function of the QWP angle and increases with the degree of polarization. For modulation by the DHFLC cell, the data derived from our electro-optic measurements are fitted using the theory of the orientational Kerr effect in FLCs. This theory in combination with the results of fitting is used to evaluate electric field dependencies of the interferometric and the Uhlmann phases.

We extend the concepts of Pancharatnam’s connection and phase difference of optical beams to cover random, stationary, partially polarized quasimonochromatic light. The geometric and dynamic structures of the phase are assessed within the framework of classical statistical polarization theory when the beam undergoes a cyclic, unitary polarization-state evolution. The existence of the two phase types is confirmed experimentally by conducting an interferometric measurement where the phase changes are found from the variations in the position of an intensity fringe pattern. The formalism also leads to a definition of the geometric phase for partially polarized beams, which is consistent with the results on mixed (qubit) quantum states.

We theoretically investigate a novel mechanism for controlling the quantum degree of polarization of single- and multi-photon light fields through the combined effects of birefringence and dispersion in optical media. While birefringence alone introduces a unitary phase shift between horizontal (H) and vertical (V) polarization modes, the inclusion of dispersion produces frequency-dependent effects that couple polarization with spectral degrees of freedom, thereby inducing decoherence and transforming the quantum state into a mixed state. By employing an electro-optically controlled nematic liquid crystal as the birefringent medium, this decoherence process can be harnessed to achieve tunable control of the quantum degree of polarization. We model this voltage-dependent tunability theoretically and propose methods for experimental verification.

We theoretically investigate a novel mechanism for controlling the quantum degree of polarization of single- and multi-photon light fields through the combined effects of birefringence and dispersion in optical media. While birefringence alone introduces a unitary phase shift between horizontal (H) and vertical (V) polarization modes, the inclusion of dispersion produces frequency-dependent effects that couple polarization with spectral degrees of freedom, thereby inducing decoherence and transforming the quantum state into a mixed state. By employing an electro-optically controlled nematic liquid crystal as the birefringent medium, this decoherence process can be harnessed to achieve tunable control of the quantum degree of polarization. We model this voltage-dependent tunability theoretically and propose methods for experimental verification.

This article studies,both theoretically and experimentally,how the degree of polarization and the polarization state of polarized light affect the normalized second order correlation g(2) in Hanbury Brown-Twiss experiment.In the experiment,the plane polarized light is changed into elliptically polarized light by passing it through a 1/4 wave plate.By rotating the wave plate,the polarization state of light can be changed.Two beams of light with mutually perpendicular vibration direction,same propagation direction and random phase difference are compounded into a partly polarized light.By adjusting the intensity of one beam of the light,the degree of polarization can be changed.It is shown that for polarized light,the state of polarization causes no change in g(2).On the other hand,for light with different degrees of polarization(P),g(2) is a quadratic function of P.For natural light,P=0,and the maximum g(2) in theory is 1.5;for polarized light,P=1,and the maximum g(2) in theory is 2.

Photon pairs produced by type-I and type-II parametric down-conversion are passed through a Michelson interferometer. Two quarter-wave plates in one arm of the interferometer allow variation of the polarization state of the photons. We investigate experimentally the geometric phase or Pancharatnam phase acquired by single photons and photon pairs dependent on the solid angle that is subtended by the circuit that represents the varying state of polarization on the Poincar\'e sphere. It is found that the geometric phase acquired by the pair depends on the initial polarization state of the two photons. If both photons are in equal states of linear polarization, we observe a doubling of the geometric phase compared to single photons; in the case of orthogonal states of linear polarization, the geometric phase is completely canceled. Our results show the role of Pancharatnam's phase in nonclassical two-photon interference phenomena and the interplay between the geometric phase and the dynamical phase in these phenomena.