WO2015014709A1 - Polarimètre basé sur une réfraction conique et procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée - Google Patents

Polarimètre basé sur une réfraction conique et procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée Download PDF

Info

Publication number
WO2015014709A1
WO2015014709A1 PCT/EP2014/065918 EP2014065918W WO2015014709A1 WO 2015014709 A1 WO2015014709 A1 WO 2015014709A1 EP 2014065918 W EP2014065918 W EP 2014065918W WO 2015014709 A1 WO2015014709 A1 WO 2015014709A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
polarimeter
input electromagnetic
electromagnetic radiation
polarization state
Prior art date
Application number
PCT/EP2014/065918
Other languages
English (en)
Inventor
Jordi Mompart Penina
Alejandro Turpin Aviles
Todor Kirilov Kalkandjiev
Alba PEINADO CAPDEVILA
Angel LIZANA TUTUSAUS
Juan Ignacio Pedro CAMPOS COLOMA
Original Assignee
Universitat Autonoma De Barcelona
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Universitat Autonoma De Barcelona filed Critical Universitat Autonoma De Barcelona
Publication of WO2015014709A1 publication Critical patent/WO2015014709A1/fr

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J4/00—Measuring polarisation of light
    • G01J4/04—Polarimeters using electric detection means

Definitions

  • the present invention generally relates, in a first aspect, to a polarimeter based on conical refraction, and more particularly to a polarimeter adapted for the unambiguous determination of any polarization state of an input electromagnetic radiation.
  • a second aspect of the invention concerns to a method for determining the polarization state of an input electromagnetic radiation using the polarimeter of the first aspect.
  • Polarimeters are the basic devices to measure the polarization of the light (Stokes polarimeters) or characterizing the polarimetric properties of a polarizing sample (Mueller polarimeters) from radiometric measurements. This polarimetric information is crucial in a large number of applications, such as in medicine, to enhance the image contrast of samples [1]; in material characterization, to determine their thickness and refraction indices [2]; or in astronomy, to obtain quantitative information of stars [3], among others.
  • Stokes polarimeters determine the polarization of a light beam by projecting the studied incident light over a set of different polarization analyzers, known as Polarization System Analyzer (PSA). If the PSA includes as minimum four linearly independent polarizing analyzers, the polarimetric information of the light beam is fully determined, conforming a complete Stokes polarimeter.
  • PSA Polarization System Analyzer
  • a visual way to determine if a certain polarimeter is able to perform complete polarimetric measurements is to represent the set of polarizing analyzers on the Poincare sphere [4].
  • the polarizing analyzers are confined in a plane (i.e. a slide of the Poincare sphere), the resulting polarimeter is incomplete.
  • the PSA only contains the polarizing analyzers placed in the sphere equator (i.e. linear polarized states), the elliptical polarizing content is not determined.
  • the PSA arrangement confines a certain volume in the Poincare sphere, one obtains a complete polarimeter [5,6].
  • polarimeters can be classified depending on the acquisition method in which they are based on [14]: time sequential measurements [5,7,8], polarization modulation [9], division of aperture [10] and division of amplitude [1 1 ].
  • time sequential polarimeters and polarization modulator based polarimeters require of mechanical movements of polarizing elements [12] or of electrical addressing to liquid crystal panels [5,7] to generate the different polarization analyzers.
  • CR light ring splits into two concentric bright rings separated by a dark (Poggendorff) ring under conditions of Ro » wo, where wo is the waist radius of the focused input beam. Additionally, wo is also the width of each of these bright rings.
  • the biaxial crystal projects the input beam into an infinite number of linearly polarized states. If the input beam is circularly polarized or unpolarized, the azimuthal intensity along the ring is constant. In contrast, for linearly polarized input beams the light ring possesses a point of null intensity and a maximum intensity point placed diagonally opposite to the first one.
  • a refractive arrangement configured for conically refracting an input electromagnetic radiation characterized by a polarization state so as to provide a light spatial pattern corresponding to said polarization state
  • a light analysis arrangement configured for receiving and analysing said light spatial pattern and for determining the polarization state of the input electromagnetic radiation according to the analysed spatial pattern.
  • IMaX a polarimeter based on Liquid Crystal Variable Retarders for an aerospace mission
  • the present invention concerns, in a first aspect, to a polarimeter based on conical refraction, comprising:
  • a refractive arrangement configured for conically refracting an input electromagnetic radiation characterized by a polarization state so as to provide a light spatial pattern corresponding to said polarization state
  • a light analysis arrangement configured for receiving and analysing said light spatial pattern and for determining the polarization state of the input electromagnetic radiation according to the analysed spatial pattern.
  • the polarimeter of the first aspect of the present invention in a characteristic manner, has the next features:
  • a division-of-amplitude device configured and arranged for amplitude dividing said input electromagnetic radiation into first and second input electromagnetic radiations
  • said refractive arrangement is arranged in a first arm of the polarimeter configured for receiving said first input electromagnetic radiation
  • the polarimeter further comprises a second arm configured for receiving said second input electromagnetic radiation, where said second arm includes a static polarizing element that modifies in a controlled way the polarization content of the second input electromagnetic radiation, rotating its polarization state on the Poincare sphere, and a further refractive arrangement configured for conically refracting said second input electromagnetic radiation once it has passed through said static polarizing element, so as to provide a light spatial pattern corresponding to its polarization state;
  • said light analysis arrangement is also configured for receiving and analysing said light spatial pattern provided by said further refractive arrangement and for determining the polarization state of the input electromagnetic radiation according to both analysed light spatial patterns.
  • said static polarizing element is a quarter-wave plate (QWP).
  • said static polarizing element is an optical fibre element.
  • said input electromagnetic radiations are Gaussian light beams or light beams having at least divergence characteristics similar to the ones of a Gaussian light beam.
  • each of said refractive arrangements include at least one conical refraction biaxial crystal configured for providing said light spatial pattern in the form of a light ring projected on a plane, such as the Lloyd plane.
  • Said light analysis arrangement comprises, according to an embodiment, first and second photo-detectors arranged for receiving the light spatial patterns provided by the refractive arrangements of, respectively, the first and second arms and translating them into corresponding first and second electrical patterns, and the light analysis arrangement further comprises processing means configured and arranged for receiving, processing and analysing said first and second electrical patterns for determining the polarization state of the input electromagnetic radiation.
  • said first and second photo-detectors generate said first and second electrical patterns with magnitudes proportional to the light intensities received.
  • Each of said first and second photo-detectors comprises, for a preferred embodiment, a light sensor array arrangement, such as an image sensor of any image acquisition technology based on a pixelated array, for instance a charge-coupled device (CCD) camera, a Complementary Metal Oxide Semiconductor (CMOS) sensor or an active-pixel sensor.
  • a light sensor array arrangement such as an image sensor of any image acquisition technology based on a pixelated array, for instance a charge-coupled device (CCD) camera, a Complementary Metal Oxide Semiconductor (CMOS) sensor or an active-pixel sensor.
  • CCD charge-coupled device
  • CMOS Complementary Metal Oxide Semiconductor
  • the polarimeter of the first aspect of the invention further comprises, for an embodiment, calibration means for performing an accurate alignment of the incidence angle of some or all of the above mentioned input electromagnetic radiations and/or for compensating possible polarization defects of the optical elements of the polarimeter.
  • the polarimeter is a static polarimeter, having means for avoiding any movement of the elements involved in the polarimeter.
  • these are configured, preferably, for conically refracting an input electromagnetic radiation of any wavelength to which the refractive arrangement is transparent, including wavelengths out of the visible spectra.
  • a second aspect of the invention relates to a method for determining the polarization state of an input electromagnetic radiation, comprising using the light analysis arrangement of the polarimeter of the first aspect for performing said analysis of said light spatial patterns, or of electrical patterns translated therefrom, and the determination of the polarization state of the input electromagnetic radiation according to the result of said analysis, said analysis including comparing both of said light spatial patterns.
  • said light spatial patterns are light rings that exhibit different intensity distributions depending on the input electromagnetic radiation (as for instance, constant intensity distributions or broken light rings with diametrically opposite maximum and minimum intensity positions).
  • the method is able to determine any polarization state of the input electromagnetic radiation, including fully polarized radiation (linear polarization, right and left handed elliptical polarization, right and left handed circular polarization), partial polarized radiation and fully unpolarized radiation.
  • the method determines the polarization of the electromagnetic radiation, by comparing the intensity distributions of the light patterns of the first and second arms of the polarimeter, achieving different pairs of intensity patterns for each particular input polarization.
  • the method of the second aspect of the invention comprises:
  • the polarization state of the input electromagnetic radiation is a circularly polarized state if the light pattern of the first arm of the polarimeter is a light ring with constant intensity distribution and the light pattern of the second arm of the polarimeter is a broken light ring with diametrically opposite maximum and null intensity positions, and depending on the locations of said maximum and null intensity positions determining that the circularly polarized light is right or left handed.
  • Fig. 1 schematically shows the polarimeter of the first aspect of the invention, for a preferred embodiment
  • Fig. 2 show the polarizing analyzers (Pas) of both arms of the polarimeter of the first aspect of the invention, represented upon the Poincare sphere, by means of the illustrated lines corresponding to the linear detection arm and to the elliptical detection arm (assuming that the QWP is at 0°);
  • Fig. 3 are experimental images acquired by cameras of arm 1 (a-g) and arm 2 (h- n) of the polarimeter of the first aspect of the invention, when illuminating with linearly polarized light at 0° (a,h), at 90° (b,i), at 45° (c,j), at 135° (d,k), with circularly polarized light right handed (e,l) and left handed (f,m) and with unpolarized light (g,n); and
  • Fig. 4 show different simulated intensity profile in continuous line and experimental intensity profile in spots, as function of ⁇ , the position along the ring of arm 1 (a-g) and arm 2 (h-n); when illuminating with linearly polarized light at 0° (a,h), at 90° (b,i), at 45° (c,j), at 135° (d,k), with circularly polarized light right handed (e,l) and left handed (f,m) and with unpolarized light (g,n).
  • linearly polarized light at 0° (a,h), at 90° (b,i), at 45° (c,j), at 135° (d,k), with circularly polarized light right handed (e,l) and left handed (f,m) and with unpolarized light (g,n).
  • Fig. 1 the design of a polarimeter based on two biaxial crystals is proposed, sketched in Fig. 1 , as an embodiment of the first aspect of the invention, and which includes:
  • BS such as a light beam splitter
  • a first arm A1 including, arranged aligned according to a first optical axis, from a first output of the light beam splitter BS: a focusing lens L1 , a conical refraction biaxial crystal C1 , a magnifying lens L2 arranged beyond the focal plane Pf1 of said conical refraction biaxial crystal C1 for magnifying the light ring projected thereon, and a first photo-detector FD1 , such as a CCD camera, arranged for receiving the magnified light ring,
  • a second arm A2 including, arranged aligned according to a second optical axis, from a second output of the light beam splitter BS: a focusing lens L3, a quarter wave plate QWP, a conical refraction biaxial crystal C2, a magnifying lens L4 arranged beyond the focal plane Pf2 of said conical refraction biaxial crystal C2 for magnifying the light ring projected thereon, and a second photo-detector FD2, such as a CCD camera, arranged for receiving the magnified light ring; and
  • -a light analysis arrangement configured for receiving and analysing the light spatial patterns provided though by both arms A1 , A2, for determining the polarization state of the input electromagnetic radiation Sj n according to both analysed light spatial patterns
  • the light analysis arrangement comprises, for the illustrated embodiment, the first and second CCD cameras FD1 , FD2, which translated the received light patterns into corresponding first and second electrical patterns
  • processing means SP configured and arranged for receiving, processing and analysing said first and second electrical patterns for determining the polarization state of the input electromagnetic radiation.
  • the processing means SP can be local, remote, partially local and/or partially remote, internal and/or external to the circuitry associated to the CCD cameras, and/or wired or wireless communicated therewith.
  • the operation of the polarizer is as follows:
  • the studied light beam Si n by means of a division of amplitude device BS, is split in two sub-beams Sj n i and Sj n 2 which are analyzed separately by two different polarizing analyzer arms A1 and A2.
  • Both biaxial crystals were cut with one of the optic axes perpendicular to the slab faces.
  • the focusing lens L1 , L3 focuses the beam Sj n i , Sj n 2, which passes along the optical axis of the biaxial crystal C1 , C2, forming the C ring at its focal plane Pf1 , Pf2.
  • the magnifying lens L2, L4 images the CR ring into the CCD camera FD1 , FD1 , with a certain magnification.
  • the intensity distribution acquired by the cameras FD1 , FD1 will depend on the incident state of polarization Si n .
  • the obtained intensity pattern can be understood as the result of projecting the incident beam Sin (in fact sub-beam Sj n i ) over a set of linear polarizers arranged in a circle.
  • the orientation of the transmission axis of those polarizers is rotated (from 0° to 180°) over the complete circle.
  • the second arm A2 is needed, which includes a quarter waveplate QWP before the biaxial crystal C2.
  • the intensity pattern in the plane Pf2 for the second arm A2 can be understood as the result of projecting the incident beam Sin (in fact sub-beam Sin2) over a QWP and then, over the set of rotated polarizers arranged in a circle.
  • PAs will be expressed as function of ⁇ , the angular position at the ring. Finally, the intensity distribution measured by the two cameras will be the projection of the incident
  • Eq. (4) describes the intensity distribution along the ring due to the CR phenomenon for any input state of polarization. This equation is a generalization of the equations presented in [18], describing the particular cases of linearly and circularly fully polarized states.
  • the PAs of both arms are plotted upon the Poincare sphere in Fig. 2. If the orientation of the QWP is rotated an angle ⁇ , the curve of the PAs represented upon the Poincare sphere corresponding to the arm A2 will be rotated 2 ⁇ over the S3 axis. Note that by using only a single arm, the PAs draw a plane in the Poincare sphere and consequently, they constitute an incomplete polarimeter. In particular, the PAs from first arm A1 (indicated in the Figure as "Linear detection”) do not have information about S3 and, the ones from second arm A2 (indicated in the Figure as "Elliptical detection”) do not measure the S2 component. However, when the whole system is considered the polarimeter is complete since the PAs represented upon the sphere are enclosing a certain volume.
  • the CN a metric widespread used in polarimeter design
  • the EWV indicator is also calculated for our proposed configuration. From simulations, it can be observed that the EWV value depends on the number of PAs used in the Stokes measurement [5]: the larger the number of PAs used, the smaller the EWV value obtained. For the case of 360 PAs per arm, i.e. 720 in total, the EWV is 0.0153. This value is much smaller than the one reported in [5] for 100 PAs (0.1 ).
  • the present inventors have experimentally implemented the arrangement of Fig. 1 and different input polarization states are analyzed.
  • the input light is obtained from a 640 nm diode laser coupled to a monomode fiber.
  • the two biaxial crystals C1 , C2 used in the setup were cut from a monoclinic centrosymmetric KGd(W0 4 ) 2 crystal.
  • Their polished entrance cross-section 6x4 mm 2
  • Their polished entrance have parallelism with less than 10 arc sec, and they are perpendicular to one of the two optic crystal axes within 1 .5 mrad misalignment angle.
  • Fig. 3 shows the two experimental images acquired by the two cameras FD1 , FD2 when seven particular states of polarization (SOPs) illuminate the system.
  • the used SOPs are linearly polarized light at 0°, 90°, 45° and 135°, right and left handed circularly polarized light and unpolarized light.
  • the first row of Fig. 3 corresponds to the first camera, i.e. projecting over linear polarization analyzers.
  • the intensity patterns consist in broken rings with a maximum and a null of intensity in diametrically opposite positions in the ring.
  • the polarimeter and method of the present invention constitute a new concept for Stokes vector metrology by means of analyzing the characteristic intensity pattern associated to the conical refraction phenomenon occurring in biaxial crystals.
  • This idea is developed by proposing the design of a division of amplitude complete Stokes polarimeter based on two biaxial crystals. Just one division of amplitude is required to completely characterize any state of polarization, including partially polarized and unpolarized light.
  • the proposed design describes a static polarimeter and thus, no mechanical movements or electrical signal addressing would be needed in a future implementation.
  • the polarimeter of the first aspect of the invention further comprises calibration means for performing an accurate alignment of the incidence angle of some or all of the above mentioned input electromagnetic radiations and/or for compensating possible polarization defects of the optical elements of the polarimeter.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

La présente invention concerne un polarimètre basé sur une réfraction conique et un procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée. Le polarimètre comprend : - un dispositif de division d'amplitude (BS) servant à diviser l'amplitude d'un rayonnement électromagnétique d'entrée (Sin) caractérisé par un état de polarisation en un premier rayonnement électromagnétique d'entrée (Sin1) et en un second rayonnement électromagnétique d'entrée (Sin2), - un premier bras (A1) et un second bras (A2) comprenant chacun un agencement réfractif (C1, C2) conçu pour réfracter en cône ledit premier rayonnement électromagnétique d'entrée (Sin1) et ledit second rayonnement électromagnétique d'entrée (Sin2) afin de former des motifs spatiaux lumineux respectifs correspondant à leur état de polarisation; et - un agencement d'analyse de lumière conçu pour recevoir et analyser lesdits motifs spatiaux lumineux et pour déterminer l'état de polarisation du rayonnement électromagnétique d'entrée (Sin) sur la base des deux motifs spatiaux analysés. Le procédé comprend l'utilisation de l'agencement d'analyse de lumière du polarimètre de l'invention pour déterminer l'état de polarisation du rayonnement électromagnétique d'entrée (Sin).
PCT/EP2014/065918 2013-08-02 2014-07-24 Polarimètre basé sur une réfraction conique et procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée WO2015014709A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP13382317 2013-08-02
EP13382317.9 2013-08-02

Publications (1)

Publication Number Publication Date
WO2015014709A1 true WO2015014709A1 (fr) 2015-02-05

Family

ID=48948371

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2014/065918 WO2015014709A1 (fr) 2013-08-02 2014-07-24 Polarimètre basé sur une réfraction conique et procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée

Country Status (1)

Country Link
WO (1) WO2015014709A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108036744A (zh) * 2017-11-23 2018-05-15 华中科技大学 一种纳米薄膜制备过程的大面积动态测量装置及方法
CN114739545A (zh) * 2022-04-12 2022-07-12 中国人民解放军陆军工程大学 基于pbs的高频偏振信息解调系统及定标装方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5337146A (en) * 1992-03-30 1994-08-09 University Of New Orleans Diffraction-grating photopolarimeters and spectrophotopolarimeters
US20060193044A1 (en) * 2005-02-07 2006-08-31 Blum Joel R Conical refraction polarimeter
US20090237662A1 (en) * 2008-03-14 2009-09-24 Teledyne Scientific & Imaging, Llc Real-time, hybrid amplitude-time division polarimetric imaging camera

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5337146A (en) * 1992-03-30 1994-08-09 University Of New Orleans Diffraction-grating photopolarimeters and spectrophotopolarimeters
US20060193044A1 (en) * 2005-02-07 2006-08-31 Blum Joel R Conical refraction polarimeter
US20090237662A1 (en) * 2008-03-14 2009-09-24 Teledyne Scientific & Imaging, Llc Real-time, hybrid amplitude-time division polarimetric imaging camera

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ALBA PEINADO ET AL: "Conical refraction as a tool for polarization metrology", OPTICS LETTERS, OPTICAL SOCIETY OF AMERICA, US, vol. 38, no. 20, 15 October 2013 (2013-10-15), pages 4100 - 4103, XP001584910, ISSN: 0146-9592, [retrieved on 20131009], DOI: 10.1364/OL.38.004100 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108036744A (zh) * 2017-11-23 2018-05-15 华中科技大学 一种纳米薄膜制备过程的大面积动态测量装置及方法
CN108036744B (zh) * 2017-11-23 2019-06-11 华中科技大学 一种纳米薄膜制备过程的大面积动态测量装置及方法
CN114739545A (zh) * 2022-04-12 2022-07-12 中国人民解放军陆军工程大学 基于pbs的高频偏振信息解调系统及定标装方法
CN114739545B (zh) * 2022-04-12 2023-09-22 中国人民解放军陆军工程大学 基于pbs的高频偏振信息解调系统及定标装方法

Similar Documents

Publication Publication Date Title
Snik et al. Spectral modulation for full linear polarimetry
KR101460802B1 (ko) 위상차 측정 방법 및 장치
WO2001007881A9 (fr) Polarimetres/ ellipsometres spectroscopiques a detection parallele
US7202950B2 (en) Retardance measurement system and method
CA2547788A1 (fr) Procede et dispositif de lumiere polarisante pour la determination de l'epaisseur de paroi et d'orientation de fibrilles de fibres cellulosiques
CN107923793B (zh) 小型光谱仪和光谱方法
WO2008128024A1 (fr) Appareil photo de polarimétrie d'instantané compact
US9625369B2 (en) Polychromatic polarization state generator and its application for real-time birefringence imaging
US10634607B1 (en) Snapshot ellipsometer
CN108496066B (zh) 微型光谱仪和用于在成像模式与光谱仪模式之间切换微型光谱仪的方法
CN109856058B (zh) 一种高分辨率实时偏振光谱分析装置及方法
Peinado et al. Optimization, tolerance analysis and implementation of a Stokes polarimeter based on the conical refraction phenomenon
Boulbry et al. Improved method for calibrating a Stokes polarimeter
US11530953B2 (en) Snapshot Mueller matrix polarimeter
Negara et al. Simplified Stokes polarimeter based on division-of-amplitude
WO2015014709A1 (fr) Polarimètre basé sur une réfraction conique et procédé de détermination de l'état de polarisation d'un rayonnement électromagnétique d'entrée
Ding et al. Demonstration of compact in situ Mueller-matrix polarimetry based on binary polarization rotators
Wolfe et al. High-speed imaging polarimeter
CN107314839A (zh) 基于穆勒矩阵的应力检测装置及方法
Li et al. Compact static birefringent spectral range enhanced Fourier transform imaging spectrometer
US11391666B1 (en) Snapshot ellipsometer
CZ20001015A3 (en) Analysis method of spectral distribution of light and apparatus for making the same
US9772225B2 (en) Spectroscopic device
Chang et al. LCVR-based Stokes polarimeter: principles and evaluation
Smith Polarization metrology moves beyondhome-brewed'solutions

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14744308

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14744308

Country of ref document: EP

Kind code of ref document: A1