Jones calculus

Last updated

In optics, polarized light can be described using the Jones calculus, [1] invented by R. C. Jones in 1941. Polarized light is represented by a Jones vector, and linear optical elements are represented by Jones matrices . When light crosses an optical element the resulting polarization of the emerging light is found by taking the product of the Jones matrix of the optical element and the Jones vector of the incident light. Note that Jones calculus is only applicable to light that is already fully polarized. Light which is randomly polarized, partially polarized, or incoherent must be treated using Mueller calculus.

Contents

Jones vector

The Jones vector describes the polarization of light in free space or another homogeneous isotropic non-attenuating medium, where the light can be properly described as transverse waves. Suppose that a monochromatic plane wave of light is travelling in the positive z-direction, with angular frequency ω and wave vector k = (0,0,k), where the wavenumber k = ω/c. Then the electric and magnetic fields E and H are orthogonal to k at each point; they both lie in the plane "transverse" to the direction of motion. Furthermore, H is determined from E by 90-degree rotation and a fixed multiplier depending on the wave impedance of the medium. So the polarization of the light can be determined by studying E. The complex amplitude of E is written:

Note that the physical E field is the real part of this vector; the complex multiplier serves up the phase information. Here is the imaginary unit with .

The Jones vector is

Thus, the Jones vector represents the amplitude and phase of the electric field in the x and y directions.

The sum of the squares of the absolute values of the two components of Jones vectors is proportional to the intensity of light. It is common to normalize it to 1 at the starting point of calculation for simplification. It is also common to constrain the first component of the Jones vectors to be a real number. This discards the overall phase information that would be needed for calculation of interference with other beams.

Note that all Jones vectors and matrices in this article employ the convention that the phase of the light wave is given by , a convention used by Hecht. Under this convention, increase in (or ) indicates retardation (delay) in phase, while decrease indicates advance in phase. For example, a Jones vectors component of () indicates retardation by (or 90 degrees) compared to 1 (). Collett uses the opposite definition for the phase (). Also, Collet and Jones follow different conventions for the definitions of handedness of circular polarization. Jones' convention is called: "From the point of view of the receiver", while Collett's convention is called: "From the point of view of the source." The reader should be wary of the choice of convention when consulting references on the Jones calculus.

The following table gives the 6 common examples of normalized Jones vectors.

PolarizationJones vectorTypical ket notation[ citation needed ]
Linear polarized in the x direction
Typically called "horizontal"
Linear polarized in the y direction
Typically called "vertical"
Linear polarized at 45° from the x axis
Typically called "diagonal" L+45
Linear polarized at −45° from the x axis
Typically called "anti-diagonal" L−45
Right-hand circular polarized
Typically called "RCP" or "RHCP"
Left-hand circular polarized
Typically called "LCP" or "LHCP"

A general vector that points to any place on the surface is written as a ket . When employing the Poincaré sphere (also known as the Bloch sphere), the basis kets ( and ) must be assigned to opposing (antipodal) pairs of the kets listed above. For example, one might assign = and = . These assignments are arbitrary. Opposing pairs are

The polarization of any point not equal to or and not on the circle that passes through is known as elliptical polarization.

Jones matrices

The Jones matrices are operators that act on the Jones vectors defined above. These matrices are implemented by various optical elements such as lenses, beam splitters, mirrors, etc. Each matrix represents projection onto a one-dimensional complex subspace of the Jones vectors. The following table gives examples of Jones matrices for polarizers:

Optical elementJones matrix
Linear polarizer with axis of transmission horizontal [2]

Linear polarizer with axis of transmission vertical [2]

Linear polarizer with axis of transmission at ±45° with the horizontal [2]

Linear polarizer with axis of transmission angle from the horizontal [2]

Right circular polarizer [2]

Left circular polarizer [2]

Phase retarders

A phase retarder is an optical element that produces a phase difference between two orthogonal polarization components of a monochromatic polarized beam of light. [3] Mathematically, using kets to represent Jones vectors, this means that the action of a phase retarder is to transform light with polarization

to

where are orthogonal polarization components (i.e. ) that are determined by the physical nature of the phase retarder. In general, the orthogonal components could be any two basis vectors. For example, the action of the circular phase retarder is such that

However, linear phase retarders, for which are linear polarizations, are more commonly encountered in discussion and in practice. In fact, sometimes the term "phase retarder" is used to refer specifically to linear phase retarders.

Linear phase retarders are usually made out of birefringent uniaxial crystals such as calcite, MgF2 or quartz. Plates made of these materials for this purpose are referred to as waveplates. Uniaxial crystals have one crystal axis that is different from the other two crystal axes (i.e., ninj = nk). This unique axis is called the extraordinary axis and is also referred to as the optic axis. An optic axis can be the fast or the slow axis for the crystal depending on the crystal at hand. Light travels with a higher phase velocity along an axis that has the smallest refractive index and this axis is called the fast axis. Similarly, an axis which has the largest refractive index is called a slow axis since the phase velocity of light is the lowest along this axis. "Negative" uniaxial crystals (e.g., calcite CaCO3, sapphire Al2O3) have ne < no so for these crystals, the extraordinary axis (optic axis) is the fast axis, whereas for "positive" uniaxial crystals (e.g., quartz SiO2, magnesium fluoride MgF2, rutile TiO2), ne > no and thus the extraordinary axis (optic axis) is the slow axis. Other commercially available linear phase retarders exist and are used in more specialized applications. The Fresnel rhombs is one such alternative.

Any linear phase retarder with its fast axis defined as the x- or y-axis has zero off-diagonal terms and thus can be conveniently expressed as

where and are the phase offsets of the electric fields in and directions respectively. In the phase convention , define the relative phase between the two waves as . Then a positive (i.e. > ) means that doesn't attain the same value as until a later time, i.e. leads . Similarly, if , then leads .

For example, if the fast axis of a quarter waveplate is horizontal, then the phase velocity along the horizontal direction is ahead of the vertical direction i.e., leads . Thus, which for a quarter waveplate yields .

In the opposite convention , define the relative phase as . Then means that doesn't attain the same value as until a later time, i.e. leads .

Phase retardersCorresponding Jones matrix
Quarter-wave plate with fast axis vertical [4] [note 1]
Quarter-wave plate with fast axis horizontal [4]
Quarter-wave plate with fast axis at angle w.r.t the horizontal axis
Half-wave plate rotated by [5]
Half-wave plate with fast axis at angle w.r.t the horizontal axis [6]
General Waveplate (Linear Phase Retarder) [3]
Arbitrary birefringent material (Elliptical phase retarder) [3] [7]

The Jones matrix for an arbitrary birefringent material is the most general form of a polarization transformation in the Jones calculus; it can represent any polarization transformation. To see this, one can show

The above matrix is a general parametrization for the elements of SU(2), using the convention

where the overline denotes complex conjugation.

Finally, recognizing that the set of unitary transformations on can be expressed as

it becomes clear that the Jones matrix for an arbitrary birefringent material represents any unitary transformation, up to a phase factor . Therefore, for appropriate choice of , , and , a transformation between any two Jones vectors can be found, up to a phase factor . However, in the Jones calculus, such phase factors do not change the represented polarization of a Jones vector, so are either considered arbitrary or imposed ad hoc to conform to a set convention.

The special expressions for the phase retarders can be obtained by taking suitable parameter values in the general expression for a birefringent material. [7] In the general expression:

Note that for linear retarders, = 0 and for circular retarders, = ± /2, = /4. In general for elliptical retarders, takes on values between - /2 and /2.

Axially rotated elements

Assume an optical element has its optic axis[ clarification needed ] perpendicular to the surface vector for the plane of incidence [ clarification needed ] and is rotated about this surface vector by angle θ/2 (i.e., the principal plane through which the optic axis passes,[ clarification needed ] makes angle θ/2 with respect to the plane of polarization of the electric field[ clarification needed ] of the incident TE wave). Recall that a half-wave plate rotates polarization as twice the angle between incident polarization and optic axis (principal plane). Therefore, the Jones matrix for the rotated polarization state, M(θ), is

where

This agrees with the expression for a half-wave plate in the table above. These rotations are identical to beam unitary splitter transformation in optical physics given by

where the primed and unprimed coefficients represent beams incident from opposite sides of the beam splitter. The reflected and transmitted components acquire a phase θr and θt, respectively. The requirements for a valid representation of the element are [8]

and

Both of these representations are unitary matrices fitting these requirements; and as such, are both valid.

Arbitrarily rotated elements

Finding the Jones matrix, J(α, β, γ), for an arbitrary rotation involves a three-dimensional rotation matrix. In the following notation α, β and γ are the yaw, pitch, and roll angles (rotation about the z-, y-, and x-axes, with x being the direction of propagation), respectively. The full combination of the 3-dimensional rotation matrices is the following:

Using the above, for any base Jones matrix J, you can find the rotated state J(α, β, γ) using:

[5]

The simplest case, where the Jones matrix is for an ideal linear horizontal polarizer, reduces then to:

where ci and si represent the cosine or sine of a given angle "i", respectively.


See Russell A. Chipman and Garam Yun for further work done based on this. [9] [10] [11] [12] [13]

See also

Notes

  1. The prefactor appears only if one defines the phase delays in a symmetric fashion; that is, . This is done in Hecht [4] but not in Fowles. [2] In the latter reference the Jones matrices for a quarter-wave plate have no prefactor.

Related Research Articles

<span class="mw-page-title-main">Pauli matrices</span> Matrices important in quantum mechanics and the study of spin

In mathematical physics and mathematics, the Pauli matrices are a set of three 2 × 2 complex matrices that are traceless, Hermitian, involutory and unitary. Usually indicated by the Greek letter sigma, they are occasionally denoted by tau when used in connection with isospin symmetries.

In electrodynamics, elliptical polarization is the polarization of electromagnetic radiation such that the tip of the electric field vector describes an ellipse in any fixed plane intersecting, and normal to, the direction of propagation. An elliptically polarized wave may be resolved into two linearly polarized waves in phase quadrature, with their polarization planes at right angles to each other. Since the electric field can rotate clockwise or counterclockwise as it propagates, elliptically polarized waves exhibit chirality.

In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. The term linear polarization was coined by Augustin-Jean Fresnel in 1822. See polarization and plane of polarization for more information.

In mechanics and geometry, the 3D rotation group, often denoted SO(3), is the group of all rotations about the origin of three-dimensional Euclidean space under the operation of composition.

A nonholonomic system in physics and mathematics is a physical system whose state depends on the path taken in order to achieve it. Such a system is described by a set of parameters subject to differential constraints and non-linear constraints, such that when the system evolves along a path in its parameter space but finally returns to the original set of parameter values at the start of the path, the system itself may not have returned to its original state. Nonholonomic mechanics is an autonomous division of Newtonian mechanics.

<span class="mw-page-title-main">Bloch sphere</span> Geometrical representation of the pure state space of a two-level quantum mechanical system

In quantum mechanics and computing, the Bloch sphere is a geometrical representation of the pure state space of a two-level quantum mechanical system (qubit), named after the physicist Felix Bloch.

In rotordynamics, the rigid rotor is a mechanical model of rotating systems. An arbitrary rigid rotor is a 3-dimensional rigid object, such as a top. To orient such an object in space requires three angles, known as Euler angles. A special rigid rotor is the linear rotor requiring only two angles to describe, for example of a diatomic molecule. More general molecules are 3-dimensional, such as water, ammonia, or methane.

In particle physics, neutral particle oscillation is the transmutation of a particle with zero electric charge into another neutral particle due to a change of a non-zero internal quantum number, via an interaction that does not conserve that quantum number. Neutral particle oscillations were first investigated in 1954 by Murray Gell-mann and Abraham Pais.

A theoretical motivation for general relativity, including the motivation for the geodesic equation and the Einstein field equation, can be obtained from special relativity by examining the dynamics of particles in circular orbits about the Earth. A key advantage in examining circular orbits is that it is possible to know the solution of the Einstein Field Equation a priori. This provides a means to inform and verify the formalism.

Sinusoidal plane-wave solutions are particular solutions to the wave equation.

Photon polarization is the quantum mechanical description of the classical polarized sinusoidal plane electromagnetic wave. An individual photon can be described as having right or left circular polarization, or a superposition of the two. Equivalently, a photon can be described as having horizontal or vertical linear polarization, or a superposition of the two.

There are several equivalent ways for defining trigonometric functions, and the proofs of the trigonometric identities between them depend on the chosen definition. The oldest and most elementary definitions are based on the geometry of right triangles and the ratio between their sides. The proofs given in this article use these definitions, and thus apply to non-negative angles not greater than a right angle. For greater and negative angles, see Trigonometric functions.

The Wigner D-matrix is a unitary matrix in an irreducible representation of the groups SU(2) and SO(3). It was introduced in 1927 by Eugene Wigner, and plays a fundamental role in the quantum mechanical theory of angular momentum. The complex conjugate of the D-matrix is an eigenfunction of the Hamiltonian of spherical and symmetric rigid rotors. The letter D stands for Darstellung, which means "representation" in German.

In mathematics, the Schur orthogonality relations, which were proven by Issai Schur through Schur's lemma, express a central fact about representations of finite groups. They admit a generalization to the case of compact groups in general, and in particular compact Lie groups, such as the rotation group SO(3).

<span class="mw-page-title-main">Gravitational lensing formalism</span>

In general relativity, a point mass deflects a light ray with impact parameter by an angle approximately equal to

We take the functional theoretic algebra C[0, 1] of curves. For each loop γ at 1, and each positive integer n, we define a curve called n-curve. The n-curves are interesting in two ways.

  1. Their f-products, sums and differences give rise to many beautiful curves.
  2. Using the n-curves, we can define a transformation of curves, called n-curving.

In physics, Berry connection and Berry curvature are related concepts which can be viewed, respectively, as a local gauge potential and gauge field associated with the Berry phase or geometric phase. The concept was first introduced by S. Pancharatnam as geometric phase and later elaborately explained and popularized by Michael Berry in a paper published in 1984 emphasizing how geometric phases provide a powerful unifying concept in several branches of classical and quantum physics.

In physics and engineering, Davenport chained rotations are three chained intrinsic rotations about body-fixed specific axes. Euler rotations and Tait–Bryan rotations are particular cases of the Davenport general rotation decomposition. The angles of rotation are called Davenport angles because the general problem of decomposing a rotation in a sequence of three was studied first by Paul B. Davenport.

<span class="mw-page-title-main">Courant–Snyder parameters</span> Set of quantities in accelerator physics

In accelerator physics, the Courant–Snyder parameters are a set of quantities used to describe the distribution of positions and velocities of the particles in a beam. When the positions along a single dimension and velocities along that dimension of every particle in a beam are plotted on a phase space diagram, an ellipse enclosing the particles can be given by the equation:

References

  1. "Jones Calculus". spie.org. Retrieved 2022-08-07.
  2. 1 2 3 4 5 6 7 Fowles, G. (1989). Introduction to Modern Optics (2nd ed.). Dover. p.  35. ISBN   9780486659572.
  3. 1 2 3 P.S. Theocaris; E.E. Gdoutos (1979). Matrix Theory of Photoelasticity. Springer Series in Optical Sciences. Vol. 11 (1st ed.). Springer-Verlag. doi:10.1007/978-3-540-35789-6. ISBN   978-3-662-15807-4.
  4. 1 2 3 Eugene Hecht (2001). Optics (4th ed.). Addison-Wesley. p.  378. ISBN   978-0805385663.
  5. 1 2 "Jones Calculus". spie.org. Retrieved 2023-04-29.
  6. Gerald, A.; Burch, J.M. (1975). Introduction to Matrix Methods in Optics (1st ed.). John Wiley & Sons. p. 212. ISBN   978-0471296850.
  7. 1 2 Gill, Jose Jorge; Bernabeu, Eusebio (1987). "Obtainment of the polarizing and retardation parameters of a non-depolarizing optical system from the polar decomposition of its Mueller matrix". Optik . 76 (2): 67–71. ISSN   0030-4026.
  8. Ou, Z. Y.; Mandel, L. (1989). "Derivation of reciprocity relations for a beam splitter from energy balance". Am. J. Phys. 57 (1): 66. Bibcode:1989AmJPh..57...66O. doi:10.1119/1.15873.
  9. Chipman, R.A.; Lam, W.S.T.; Young, G. (2018). Polarized Light and Optical Systems. Optical Sciences and Applications of Light. CRC Press. ISBN   978-1-4987-0057-3 . Retrieved 2023-01-20.
  10. Chipman, Russell A. (1995). "Mechanics of polarization ray tracing". Opt. Eng. 34 (6): 1636–1645. Bibcode:1995OptEn..34.1636C. doi:10.1117/12.202061.
  11. Yun, Garam; Crabtree, Karlton; Chipman, Russell A. (2011). "Three-dimensional polarization ray-tracing calculus I: definition and diattenuation". Applied Optics . 50 (18): 2855–2865. Bibcode:2011ApOpt..50.2855Y. doi:10.1364/AO.50.002855. PMID   21691348.
  12. Yun, Garam; McClain, Stephen C.; Chipman, Russell A. (2011). "Three-dimensional polarization ray-tracing calculus II: retardance". Applied Optics. 50 (18): 2866–2874. Bibcode:2011ApOpt..50.2866Y. doi:10.1364/AO.50.002866. PMID   21691349.
  13. Yun, Garam (2011). Polarization Ray Tracing (PhD thesis). University of Arizona. hdl:10150/202979.

Further reading