Holographic recording in a photo-cross-linkable liquid crystalline copolymer using a 325-nm laser with various polarizations

• Published in: Reactive & functional polymers Vol. 70; no. 12; pp. 980 - 985
• Main Authors: Kawatsuki, Nobuhiro, Tashima, Ayaka, Manabe, Sayaka, Kondo, Mizuho, Okada, Makoto, Matsui, Shinji, Emoto, Akira, Ono, Hiroshi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.12.2010; Elsevier
• Subjects: Applied sciences; Beams (radiation); Copolymers; Diffraction efficiency; Diffraction gratings; Exact sciences and technology; Holography; Lasers; Liquid crystalline copolymer; Liquid crystals; Photoalignment; Physicochemistry of polymers; Polarization; Polarization grating; Polymers and radiations; Properties and characterization; Recording; SRG; Photoalignment; Holography; SRG; Polarization grating; Liquid crystalline copolymer; Diffraction efficiency; Photochemical crosslinking; Thermotropic state; Photoinduced effect; Holographic storage; Experimental study; Side chain; Holographic recording; Polarized radiation; Laser beam; Liquid crystal polymers; Holographic grating; Light sensitive copolymer; Molecular reorientation; Acid copolymer; Methacrylate copolymer; Cinnamic derivative copolymer
• ISSN: 1381-5148
• DOI: 10.1016/j.reactfunctpolym.2010.10.006

Surface relief (SR) gratings with a molecularly oriented structure and pure polarization hologram were fabricated on a photo-cross-linkable liquid crystalline copolymer using a 325-nm laser with various two-beam polarization modes. For intensity holography, the polarization information from the two beams simultaneously provided the molecular motion and molecular reorientation; the SR height reached up to 186 nm and the concave area revealed a molecular reorientation when the exposing beams were linearly polarized. In contrast, SR formation was negligible for polarization holography when molecular reorientation due to the polarization modulation was observed. The resulting polarization gratings changed the polarization properties of the diffraction beams, and their diffraction efficiency was reached 24%, which agreed with theoretical expectations.