Shrinkage measurement for holographic recording materials

There is an increasing demand for new holographic recording materials. One of them are photopolymers, which are becoming a classic media in this field. Their versatility is well known and new possibilities are being created by including new components, such as nanoparticles or dispersed liquid crystal molecules in classical formulations, making them interesting for additional applications in which the thin film preparation and the structural modification have a fundamental importance. Prior to obtaining a wide commercialization of displays based on photopolymers, one of the key aspects is to achieve a complete characterization of them. In this sense, one of the main parameters to estimate and control is the shrinkage of these materials. The volume variations change the angular response of the hologram in two aspects, the angular selectivity and the maximum diffraction efficiency. One criteria for the recording material to be used in a holographic data storage application is the shrinkage, maximum of 0.5%. Along this work, we compare two different methods to measure the holographic recording material shrinkage. The first one is measuring the angle of propagation for both diffracted orders ±1 when slanted gratings are recorded, so that an accurate value of the grating vector can be calculated. The second one is based on interference measurements at zero spatial frequency limit. We calculate the shrinkage for three different photopolymers: a polyvinyl alcohol acrylamide (PVA/AA) based photopolymer, one of the greenest photopolymers whose patent belongs to the Alicante University called Biophotopol and on the last place a holographic-dispersed liquid crystal photopolymer (H-PDLC).

[1]  Tina Sabel,et al.  Imaging of Volume Phase Gratings in a Photosensitive Polymer, Recorded in Transmission and Reflection Geometry , 2014 .

[2]  Ray T. Chen,et al.  Shrinkage correction of volume phase holograms for optical interconnects , 1997, Photonics West.

[3]  M. D. Lechner,et al.  Photopolymers for Optical Memories and Waveguides , 1985 .

[4]  Y. J. Liu,et al.  Holographic Polymer-Dispersed Liquid Crystals: Materials, Formation, and Applications , 2008 .

[5]  J T Gallo,et al.  Model for the effects of material shrinkage on volume holograms. , 1994, Applied optics.

[6]  Fred Askham,et al.  Photopolymer media for holographic storage at ≈ 405 nm , 2004, Optical Data Storage.

[7]  Der-Chin Su,et al.  Shrinkage- and refractive-index shift-corrected volume holograms for optical interconnects , 2002 .

[8]  Atsushi Fukumoto,et al.  Two-dimensional simulation of holographic data storage medium for multiplexed recording. , 2008, Optics express.

[9]  Yu-Chuan Su,et al.  Characterization of optically switchable holographic polymer-dispersed liquid crystal transmission gratings , 2011 .

[10]  John T. Sheridan,et al.  Refractive elements produced in photopolymer layers , 2004, SPIE Optics + Photonics.

[11]  Justin R. Lawrence,et al.  Thickness Variation of Self-processing Acrylamide-based Photopolymer and Reflection Holography , 2001 .

[12]  Friedrich-Karl Bruder,et al.  Self‐Processing, Diffusion‐Based Photopolymers for Holographic Applications , 2010 .

[13]  Technique for characterization of dimensional changes in slanted holographic gratings by monitoring the angular selectivity profile. , 2008, Optics letters.

[14]  Vincent Toal,et al.  Shrinkage during holographic recording in photopolymer films determined by holographic interferometry. , 2013, Applied optics.

[15]  V. C. Kuriakose,et al.  Self-written waveguide in methylene blue sensitized poly(vinyl alcohol)/acrylamide photopolymer material. , 2008, Applied optics.

[16]  Laszlo Solymar,et al.  A note on volume holograms , 1978 .

[17]  J. Neumann,et al.  Direct laser writing of surface reliefs in dry, self-developing photopolymer films. , 1999, Applied optics.

[19]  Yasuo Tomita,et al.  Measurement of polymerization-shrinkage evolution during curing in photopolymer with a white-light Fabry-Pérot interferometer. , 2015, Optics express.

[20]  A Márquez,et al.  Real-time interferometric characterization of a polyvinyl alcohol based photopolymer at the zero spatial frequency limit. , 2007, Applied optics.

[21]  Paul Rochon,et al.  Photoinduced liquid crystal alignment based on a surface relief grating in an assembled cell , 1999 .

[22]  Inmaculada Pascual,et al.  Influence of Thickness on the Holographic Parameters of H-PDLC Materials , 2014 .

[23]  Vincent Toal,et al.  Study of the shrinkage caused by holographic grating formation in acrylamide based photopolymer film. , 2011, Optics express.

[24]  T. Gaylord,et al.  Rigorous coupled-wave analysis of planar-grating diffraction , 1981 .

[25]  S. Gallego,et al.  Angular responses of the first and second diffracted orders in transmission diffraction grating recorded on photopolymer material. , 2003, Optics express.

[26]  Alberto Alvarez-Herrero,et al.  Shrinkage control in a photopolymerizable hybrid solgel material for holographic recording. , 2004, Applied optics.

[27]  Inmaculada Pascual,et al.  Performance analysis of the FDTD method applied to holographic volume gratings: Multi-core CPU versus GPU computing , 2013, Comput. Phys. Commun..