Source: http://tops.osa.org/josab/abstract.cfm?uri=josab-34-5-B56
Timestamp: 2019-04-22 06:36:11+00:00

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Diffractive waveplate technology presents an opportunity for designing arrays of all types of optical components. We present here different architectures of arrays of waveplate lenses and vector vortex waveplates. Due to the continuous nature of diffractive waveplate coatings and the high spatial resolution of the technology, the sizes of array elements can span from micrometers to tens of millimeters. Both fixed and electrically switchable arrays are discussed. Arrays of diffractive waveplates present new challenges and opportunities for digital light polarization holography for applications in polarizer-free displays, smart windows, optical communications, beam shaping, and other photonics technologies.
S. R. Nersisyan, N. V. Tabiryan, D. M. Steeves, and B. R. Kimball, “The promise of diffractive waveplates,” Opt. Photon. News 21(3), 40–45 (2010).
N. V. Tabiryan, D. E. Roberts, E. Serabyn, D. M. Steeves, and B. R. Kimball, “Superlens in the skies: liquid-crystal-polymer technology for telescopes,” SPIE Newsroom, February5, 2016, doi:10.1117/2.1201601.006317.
N. V. Tabiryan, S. V. Serak, S. R. Nersisyan, D. E. Roberts, B. Y. Zeldovich, D. M. Steeves, and B. R. Kimball, “Broadband waveplate lenses,” Opt. Express 24, 7091–7102 (2016).
N. V. Tabiryan, S. V. Serak, D. E. Roberts, D. M. Steeves, and B. R. Kimball, “Thin waveplate lenses of switchable focal length—new generation in optics,” Opt. Express 23, 25783 (2015).
A. M. W. Tam, F. Fan, H. S. Chen, D. Tao, V. G. Chigrinov, H. S. Kwok, and Y. S. Lin, “Continuous nanoscale patterned photoalignment for thin film Pancharatnam-Berry phase diffractive lens,” SID Symp. Dig. Tech. Pap. 46, 8 (2015).
K. Gao, H. H. Cheng, A. Bhowmik, C. McGinty, and P. Bos, “Nonmechanical zoom lens based on the Pancharatnam phase effect,” Appl. Opt. 55, 1145–1150 (2016).
K. L. Woon, M. O’Neil, P. Vlachos, M. P. Aldred, and S. M. Kelly, “Highly birefringent nematic and chiral nematic liquid crystals,” Liq. Cryst. 32, 1191–1194 (2005).
L. Nikolova and P. S. Ramanujam, Polarization Holography (Cambridge University, 2009), pp. 1–239.
S. R. Nersisyan, N. V. Tabiryan, D. M. Steeves, and B. R. Kimball, “Optical axis gratings in liquid crystals and their use for polarization insensitive optical switching,” J. Nonlinear Opt. Phys. Mater. 18, 1–47 (2009).
L. De Sio, D. Roberts, Z. Liao, S. Nersisyan, O. Uskova, L. Wickboldt, N. Tabiryan, D. Steeves, and B. Kimball, “Digital polarization holography advancing geometrical phase optics,” Opt. Express 24, 18297–18306 (2016).
S. R. Nersisyan, N. V. Tabiryan, D. Mawet, and E. Serabyn, “Improving vector vortex waveplates for high contrast coronagraphy,” Opt. Express 21, 8205–8213 (2013).
J. Hodgkinson and Q. H. Wu, Birefringent Thin Films and Polarizing Elements (World Scientific, 1997), pp. 1–379.
S. R. Nersisyan, N. V. Tabiryan, L. Hoke, D. M. Steeves, and B. Kimball, “Polarization insensitive imaging through polarization gratings,” Opt. Express 17, 1817–1830 (2009).
C. Oh and M. J. Escuti, “Achromatic diffraction from polarization gratings with high efficiency,” Opt. Lett. 33, 2287–2289 (2008).
S. R. Nersisyan, N. V. Tabiryan, D. M. Steeves, and B. R. Kimball, “Characterization of optically imprinted polarization gratings,” Appl. Opt. 48, 4062–4067 (2009).
F. M. Dickey and S. C. Holswade, eds., Laser Beam Shaping: Theory and Techniques (Marcel Dekker, 2000).
J. Kobashi, H. Yoshida, and M. Ozaki, “Planar optics with patterned chiral liquid crystals,” Nat. Photonics 10, 389–392 (2016).
S. V. Serak, U. Hrozhyk, J. Hwang, N. V. Tabiryan, D. Steeves, and B. R. Kimball, “High contrast switching of transmission due to electro-hydrodynamic effect in stacked thin systems of liquid crystals,” Appl. Opt. 55, 8506–8512 (2016).
J. P. Vernon, S. V. Serak, R. S. Hakobyan, A. K. Aleksanyan, V. P. Tondiglia, T. J. White, T. J. Bunning, and N. V. Tabiryan, “Recording polarization gratings with a standing spiral wave,” Appl. Phys. Lett. 103, 201101 (2013).
J. P. Vernon, S. V. Serak, R. S. Hakobyan, V. P. Tondiglia, T. J. White, N. V. Tabiryan, and T. J. Bunning, “Generation of light scattering states in cholesteric liquid crystals by optically controlled boundary conditions,” Crystals 3, 234–247 (2013).
S. Chandrasekhar, Liquid Crystals (Cambridge University, 1977).
V. V. Kotlyar, A. A. Almazov, S. N. Khonina, and V. A. Soifer, “Generation of phase singularity through diffracting a plane or Gaussian beam by a spiral phase plate,” J. Opt. Soc. Am. A 22, 849–861 (2005).
S. R. Nersisyan, B. R. Kimball, D. M. Steeves, and N. V. Tabiryan, “Technology of diffractive waveplates for polarizer-free displays,” in IMID/IDMC/Asia Display Digest (2010), pp. 277–278.
N. Tabiryan, D. Roberts, T. J. Bunning, D. Steeves, and B. Kimball, “4G optics: new technology extends limits to the extremes,” Photon. Spectra46–50 (2017).
N. Tabiryan, H. Xianyu, D. Roberts, Z. Liao, D. Steeves, B. Kimball, E. Serabyn, and D. Mawet, “4G optics for communications and astronomy,” in IEEE Aerospace Conference, Big Sky, Montana, 2016, pp. 1–8.
K. L. Marshall, D. Saulnier, H. Xianyu, S. Serak, and N. Tabiryan, “Liquid crystal near-IR laser beam shapers employing photoaddressable alignment layers for high-peak-power applications,” Proc. SPIE 8828, 88280N (2013).
Fig. 1. (a) Molecular orientation pattern of a square grid of round lenslets. (b) 8 × 8 LCP WLA between crossed polarizers. (c) Focusing pattern of derivative array. (d) Diffraction efficiency spectra for the template (1) and derivative (2) arrays.
Fig. 2. Central and peripheral regions of lenslets in (a, c) template and (b, d) derivative LCP WLAs under polarizing microscope; note doubling of spatial frequency in the derivative lenslet. (e, f) Distribution of anisotropy axis in a lenslet measured by Mueller matrix spectropolarimeter.
Fig. 3. Effects of WLA on a light beam. (a) Schematic depiction of focusing and defocusing of light of orthogonal circular polarization handedness by a WL. (b)–(g) Photos of an argon-ion laser beam of different polarization states (b)–(d) in the focal plane of lenslets and (e)–(g) 200 mm away from the array. The beam is (b, e) right-hand circular polarized, (c, f) left-hand circular polarized, and (d, g) linearly polarized.
Fig. 4. (a, b) Brick wall architecture of LCP WLA; (b) shows the texture between crossed polarizers. (c) Focusing pattern on a screen for He–Cd laser beam. (d) Diffraction efficiency spectra for the template (1) and derivative (2) arrays.
Fig. 5. (a, b) Fish-scale architecture of LCP WLA; (b) shows the texture between crossed polarizers. (c) Focusing pattern on a screen for white light. (d) Diffraction efficiency spectra for the template (1) and derivative (2) arrays.
Fig. 6. Anisotropy axis distribution in transition areas of lens arrays. (a) Transition area between square lenslets. (b) Fish-scale texture. (c) Magnified view of different transition areas in square array along with the waveplate axis distribution image obtained by Mueller matrix spectropolarimeter.
Fig. 7. (a, b) Photo of a square 8 × 8 LC WLA element between crossed polarizers: (a) the center and (b) the edge of a lenslet viewed with a polarizing microscope. (c)–(e) Imaging through a LC WLA: (c) photo of an eyechart without WLA; (d) photo taken with the LC WLA in front of camera; (e) photo taken with the LC WLA in front of camera during application of voltage, 10 V at 1 kHz. (f) Attenuation as a function of voltage measured for argon-ion laser beam of 514 nm wavelength.
Fig. 8. Switching of expanded and collimated argon-ion laser beams of different wavelengths using two LC WLAs: (1, 2) 457 nm; (3, 4) 488 nm; (5, 6) 514 nm. Scattering state corresponds to zero voltage. The transparent state corresponds to 10 V at 1 kHz. The screen was at 1 m distance from WLAs system.
Fig. 9. (a)–(c) Effect of the system of two NLC WLAs on a laser beam. (a) High transmission obtained for 10 V at 1 kHz on both cells. (b) Light diffusion and (c) compensation of diffusion by NLC WLAs of opposite and same signs, respectively, with no voltage. (d)–(h) Effect of WLA on visibility of an eye chart: photograph of eye chart (d) without any WLA; (e) imaged through a single NLC WLA; imaged through a system of two WLAs of (f) opposite and (g) the same signs; and (h) imaged through two WLAs at application of voltage on both arrays, 10 V at 1 kHz.
Fig. 10. (a) Photo of template LCP WLA between polarizers and (b) diffraction spectra of derivative NLC WLA at different voltages applied to the NLC cell.
Fig. 11. (a, b) Eye chart viewed through paired NLC WLAs (a) without voltage and (b) with voltage applied (10 V at 1 kHz). (c)–(f) Photos of a laser beam (532 nm) on a screen (c, d) at 0.2 m and (e, f) 1 m away from the NLC WLA pair in (c, e) with voltage and (d, f) without voltage applied.
Fig. 12. (a) Schematic depiction of a lenslet in a CLC WLA focusing a reflected LHCP beam (red lines). RHCP beam is transmitted unchanged (blue lines). (b) Photo of a CLC WLA. (c) CLC lenslet structure under microscope. (d, e) Reflected green laser beam is (d) focused and (e) defocused when incident from the opposite sides of the CLC WLA.
Fig. 13. (a, a’) Circular polarized beam propagated through a triangular aperture is reflected from a uniform planar CLC structure (no transverse modulation). (b, b’) Beam reflected from the concave and convex sides of a CLC WL. (c, c’) Beam reflected from the edges of concave and convex sides to separate the focused/defocused images from the undiffracted beam. The reflection coefficients are approximately 80%.
Fig. 14. Images of transmitted and reflected beams taken simultaneously for a CLC WL: (a) transmitted mode; (b) bandgap/reflective mode, convex side of CLC WL; (c) bandgap/reflective mode, opposite/concave side of CLC WL.
Fig. 15. Wavefronts of (a) transmitted and (b) reflected beams measured with a Shack–Hartmann wavefront sensor show less than 1 wave variation in the transmitted beam and 3 waves modulation (at 543 nm) in the reflected beam.
Fig. 16. Molecular orientation patterns (top), phase maps of a beam at the output of the VVW (middle), and far-field point spread functions (bottom) for a single and 3 × 3 arrays of VVW of q = 1 / 2 of continuous and discontinuous structure.
Fig. 17. Electrically switchable NLC array of VVWs of q = 8 at different states. (a) Diffractive state in the absence of voltage. (b) Clear state with application of voltage (10 V at 1 kHz). (c) Far field image with illumination by white light. (d) Output color of an individual VVW pixel.
Fig. 18. (a) WLA recorded on a polycarbonate substrate. (b, c) VVW array on a curved polycarbonate lens viewed (b) without polarizers and (c) between polarizers. (d, e) Switchable WLA with polycarbonate substrates (d) in voltage on and (e) voltage off states.
Fig. 19. Imaging through a system of WLAs. (a) WLAs of opposite sign with a half-wave retarder in between maintain light collimation independent of polarization. (b) In the absence of half-wave retarder, orthogonal circular polarization components of input unpolarized light are focused/defocused with double the effective focal length of an individual lens. (c) Imaging through uncompensated state and (d) compensated state.
Fig. 20. Photo of a Gaussian beam shaped into “BEAM Co.” in the far field, and the related anisotropy axis pattern produced in a LCP beam shaper.

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