Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Preparation material of high-efficiency holographic polymer dispersed liquid crystal Bragg volume grating and preparation method thereof

A technology for dispersing liquid crystals and polymers, applied in diffraction gratings, optics, nonlinear optics, etc., can solve problems such as insufficient overall effect, large liquid crystal droplets, and large scattering loss

Inactive Publication Date: 2010-08-04
FUDAN UNIV
View PDF0 Cites 12 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The prior art discloses holographic polymer-dispersed liquid crystal as an electro-optic functional material. Due to its electrically controllable optical properties, it has already been used in the research of preparing Bragg volume gratings. However, the overall effect has not been good enough. The main performance is that the diffraction efficiency is not good enough. High, less than 85%. Large scattering loss, etc., and high driving voltage, more than 18V / μm.
[0004] The main reasons for the above problems are firstly the matching degree of the optical parameters of the materials, and secondly, the control of the grating formation process parameters in the usual holographic preparation method is not good enough, such as exposure intensity and exposure time. Therefore, it is easy to form larger liquid crystal droplets.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] The mixed emulsion is composed of 35% acrylate monomer, 10% bonding agent, 0.4% initiator, 0.5% co-initiator, and 40% nematic liquid crystal. Seal it In a liquid crystal cell with a cell thickness of 10 μm, it is placed in the interference light field of a green laser for holographic exposure. The green light used in the exposure process is a continuous laser with a wavelength of 532 nm. The intensity of each laser beam is 5 milliwatts, and the exposure time is 8 second. The liquid crystal cell was left standing in the dark room for 10 minutes to realize the purpose of further completing the reaction of the monomer that has not been fully polymerized. The prepared holographic polymer dispersed liquid crystal (HPDLC) Bragg volume grating has a grating area of ​​5 × 5mm 2 The grating period is 1.1μm. The maximum diffraction efficiency can exceed 95% for the incident He-Ne light (wavelength 632.8nm) at 15.3°, and the loss of scattering and high-order diffraction is less tha...

Embodiment 2

[0019] The mixed emulsion is composed of 50% acrylate monomer, 15% bonding agent, 0.6% initiator, 1% co-initiator, and 60% nematic liquid crystal. Seal it In a liquid crystal cell with a cell thickness of 30 μm, it is placed in the interference light field of a green laser for holographic exposure. The green light used in the exposure process is a continuous laser with a wavelength of 532 nm. The intensity of each laser beam is 5 milliwatts, and the exposure time is 8 second. The liquid crystal cell was left standing in the dark room for 10 minutes to realize the purpose of further completing the reaction of the monomer that has not been fully polymerized. The prepared holographic polymer dispersed liquid crystal (HPDLC) Bragg volume grating has a grating area of ​​5 × 5mm 2 The grating period is 1.1μm. The maximum diffraction efficiency can exceed 95% for the incident He-Ne light (wavelength 632.8nm) at 15.3°, and the loss of scattering and high-order diffraction is less than ...

Embodiment 3

[0021] The composition content is respectively 35.4% of acrylate monomer, 13% of bonding agent, 0.6% of initiator, 1% of co-initiator, and 50% of nematic liquid crystal to form a mixed emulsion. Seal it in a box with a thickness of 25 μm The liquid crystal box is placed in the interference light field of the green laser for holographic exposure. The green light used in the exposure process is a continuous laser with a wavelength of 532nm. The intensity of each laser beam is 5 milliwatts, and the exposure time is 8 seconds. The liquid crystal box is in a dark room. Stand still for 10 minutes to further complete the reaction of the monomers that have not been fully polymerized, and the prepared holographic polymer dispersed liquid crystal (HPDLC) Bragg volume grating has a grating area of ​​5×5mm 2 The grating period is 1.1μm. The maximum diffraction efficiency can exceed 95% for the incident He-Ne light (wavelength 632.8nm) at 15.3°, and the loss of scattering and high-order dif...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a preparation material of a high-efficiency holographic polymer dispersed liquid crystal Bragg volume grating and a preparation method thereof. The preparation material is prepared by the following steps of: forming a mixed emulsion by an acrylate monomer with polyfunctional groups, a crosslinking agent, an initiator, a co-initiator and nematic liquid crystal; wafering the mixed emulsion into a liquid crystal box made of two transparent conductive panes; arranging the liquid crystal box in an interference light field of green laser for holographic exposure; accurately controlling exposure intensity and time; and then, enabling the liquid crystal box to stand still in a dark room for a certain time. The prepared high-efficiency holographic polymer dispersed liquid crystal Bragg volume grating has the diffraction efficiency over 95 percent and the scattering and high-order diffraction loss lower than 1 percent.

Description

technical field [0001] The invention belongs to the field of electro-optical functional materials, and relates to a high-efficiency holographic polymer dispersed liquid crystal Bragg volume grating preparation material and a preparation method thereof. Background technique [0002] It is known that the Bragg volume grating has a very high diffraction efficiency, and the diffraction efficiency of the incident light satisfying the Bragg condition can theoretically reach 100%. The diffraction efficiency is related to the incident wavelength, incident angle, volume material refractive index modulation depth (Δn), and volume grating It is related to parameters such as thickness. It has a small angular dispersion. Therefore, the Bragg volume grating is a high-resolution dispersion element and can be used in many fields such as spectral analysis, laser shaping, optical switches, and optical modulators. [0003] The prior art discloses holographic polymer-dispersed liquid crystal as...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): G02B5/18G02B6/34G03H1/02G02F1/1334
Inventor 蒲海辉尹德金高洪跃戴海涛刘建华
Owner FUDAN UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com