CN108572488B - 一种基于电解螺旋型铁电液晶的光开关 - Google Patents
一种基于电解螺旋型铁电液晶的光开关 Download PDFInfo
- Publication number
- CN108572488B CN108572488B CN201711289580.0A CN201711289580A CN108572488B CN 108572488 B CN108572488 B CN 108572488B CN 201711289580 A CN201711289580 A CN 201711289580A CN 108572488 B CN108572488 B CN 108572488B
- Authority
- CN
- China
- Prior art keywords
- liquid crystal
- ferroelectric liquid
- optical switch
- electrolytic
- layer
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
- G02F1/141—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals
-
- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/137—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
- G02F1/141—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals
- G02F1/1414—Deformed helix ferroelectric [DHL]
Landscapes
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Nonlinear Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Liquid Crystal (AREA)
Abstract
一种基于电解螺旋型铁电液晶的光开关,该发明将入射光信号进行电控导通或切断,并实现微秒级电控响应,可应用于光通讯、精密测量、光电探测、图像编码等。所述铁电液晶光开关主要包括前置偏振片、覆盖氧化铟锡导电膜的光学玻璃、取向层、铁电液晶层、后置偏振片及驱动系统。该器件基于电解螺旋型光电模式,铁电液晶在低驱动电压下螺旋结构完全解旋,不同极性的驱动电压对应解旋后的两个指向矢排布方向,在正交的起偏和检偏器内形成亮态和暗态。取向层为铁电液晶螺旋轴提供取向方向,使该发明设计铁电液晶光开关对比度达10000:1以上。
Description
技术领域
本发明涉及的铁电液晶光开关,是基于电解螺旋型铁电液晶光电模式,一种高对比度、快响应的电控光开关。
背景技术
光开关是光网络中用以对光信号实现动态控制的核心器件。光开关按照工作媒介不同,主要可分为自由空间型和波导型两大类。自由空间型按照工作原理又可分为机械类和液晶类。目前工业化最普及的光开关是机械光开关,它的原理是用机械技术对光开关的微光学光路进行控制。机械光开关的特点就是不受光波长的影响,介质损耗小,不受偏振的影响等。其缺点就是响应速度慢,体积较大,并且有机械损耗。
利用液晶材料来制备光开关,它的可靠性好,没有机械结构损耗,其最大的优势是电可调谐性,可以使用外场的改变来调节液晶光开关的状态。对于光开关,其关键性能指标包括开关对比度和开关响应时间等。对于传统的液晶光开关,使用的通常是向列相液晶,其响应时间较长,通常为毫秒量级以上,这样的响应时间是限制液晶光开关应用的短板。近年来也有一些基于特殊相态的液晶的快速响应光开关,如蓝相液晶、胆甾相液晶等,也有一些通过在普通液晶材料中引入聚合物畴结构的以提高响应速度,但是虽然提高了响应速度,但驱动电压整体偏高,因此在整个光学系统中的电耗和驱动不匹配。所以找到一种驱动电压小,响应速度快的偏振无依赖性光开关具有重要的意义。
铁电液晶具有驱动电压低、响应速度快的特点,其响应时间在几十到几百微秒,因此,利用铁电液晶的快速响应等特性制作光开关可以克服以往液晶光开关的缺陷。
发明内容
本发明的技术解决的问题是:提供一种高对比度的、快响应的铁电液晶光开关,实现微秒级响应时间,对比度大于10000:1。
本发明的技术解决方案是:一种基于电解螺旋型光电模式的铁电液晶光开关,其包括:前置偏振片、覆盖氧化铟锡导电膜的光学玻璃、取向层、铁电液晶层、后置偏振片及驱动系统,如图1所示。
前置偏振片位于铁电液晶光开关的最前端,后置偏振片位于铁电液晶光开关的最末端,将入射光束转换成线偏振光,并使偏振方向与螺旋轴轴向呈θ角,θ为铁电液晶近晶层倾角,后置偏振片透偏方向与前置偏振片呈正交方向放置。
覆盖氧化铟锡导电膜的光学玻璃及驱动系统:为铁电液晶层提供外置驱动电场,使铁电液晶分子在不同极性的电场驱动下进行均匀排布。
偶氮染料光敏取向层:将SD1层在偏振UV光(中心波长365nm,辐照度I=2mW/cm2)下曝光,取曝光剂量取18J/cm2。
铁电液晶层:将制备的覆有取向层的基板以反平行结构组盒,将1.5μm的间隔物夹在两个玻璃基板之间,使得两玻璃基板之间的间隙为1.5μm。将铁电液晶材料(FD4004N)加热至107摄氏度以上形成液态填充到上述制备的液晶盒内,然后待其冷却。铁电液晶材料FD4004N分别在72℃,85℃和105℃的温度下显示SmC*→SmA→N*→Iso的相变。在室温下,铁电液晶螺旋结构螺距为P0=350nm,自发极化Ps≈61nC/cm2,倾斜角(半锥角)θ≈22.05°。
其中,当铁电液晶层上无外置电场时,铁电液晶螺旋结构沿着取向方向排列,图2(b)展示了该光开关内铁电液晶螺旋结构存在于两基板之间。
其中,所述铁电液晶层在外置电场下,当所加载电场强度大于临界场强(Eu~0.1-1V/μm)时,螺旋结构被完全展开,各个近晶层内的铁电液晶分子均匀排布,排布方向与所加电场极性相关。
其中,在两侧玻璃基板上施加一定强度的正向电压,则铁电液晶螺旋结构将被完全展开,铁电液晶分子指向矢平行于前置偏振器透偏方向,在偏光显微镜下观察为全暗状态,如图3所示。
其中,在两侧玻璃基板上施加一定强度的负向电压,则铁电液晶螺旋结构将被完全展开,铁电液晶分子指向矢与前置偏振器透偏方向成2θ=44.1°角度方向的均匀排布,在偏光显微镜下观察为全亮状态,如图4所示。
本发明与现有铁电液晶光开关相比优点在于:该系统利用电致解旋而非表面稳定方法实现铁电液晶螺旋结构的展开,如图5所示;同时,该系统利用偶氮光敏染料对铁电液晶进行锚定能优化,对比度高。
附图说明
图1为本发明的结构图;
图2为本发明的电控响应原理图;
图3为本发明的铁电液晶在暗态下纹理图;
图4为本发明的铁电液晶在亮态下纹理图;
图5为本发明的铁电液晶光开关透过率曲线图;
图6为本发明的电控响应时间随温度变化图。
具体实施方式
在这里将详细介绍电解螺旋型铁电液晶光开关的原理及性能。
铁电液晶的电解螺旋效应的具有二值化特性的光电响应,此特性与表面稳定型铁电液晶相似,不同之处在于电解螺旋型铁电液晶没有磁滞现象,如图5所示,透射率随电压变化曲线没有磁滞回线出现,这是由于解旋机制不同所致。在方波驱动下,当电场强度大于电致消旋阈值强度的条件下,亮态透过率为:
可见,当铁电液晶倾角满足2θ=π/4,且液晶盒厚度满足半波条件
Δnd/=1/2时,电解螺旋型铁电液晶光开关透过率可达100%。
在Goldstone理论模型下,可推导出电解螺旋型铁电液晶的响应时间为:
并可以通过增加驱动电压进一步压缩响应时间,如图6所示。
本发明说明书中未作详细描述的内容属于本领域专业技术人员公知的现有技术。
Claims (7)
1.一种基于电解螺旋型铁电液晶的光开关,其特征在于,包括:
前置偏振片、覆盖氧化铟锡导电膜的光学玻璃基板、取向层、铁电液晶层、后置偏振片及驱动系统;
前置偏振片位于铁电液晶光开关的最前端,后置偏振片位于铁电液晶光开关的最末端,前置偏振片将入射光束转换成线偏振光,并使偏振方向与螺旋轴轴向呈θ角,θ为铁电液晶近晶层倾角,后置偏振片透偏方向与前置偏振片呈正交方向放置;
覆盖氧化铟锡导电膜的光学玻璃基板及驱动系统为铁电液晶层提供外置驱动电场,使铁电液晶分子在不同极性的电场驱动下进行均匀排布;
该光开关在外加电场驱动下,对入射光信号实现导通和切断的快速切换;所述的光开关是基于电解螺旋型光电模式实现的,其响应时间在100微秒以内;所述的光开关采用光敏偶氮染料SD1作为取向层,其取向层锚定能通过曝光剂量操控,使得亮暗态对比度达10000:1以上;
当铁电液晶层上无外置电场时,铁电液晶螺旋结构沿着取向方向排列。
2.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,该光开关使用的铁电液晶在外加电场下,分子的自发极化矢量与电场耦合,使铁电液晶螺旋结构发生解旋。
3.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,该光开关采用光敏偶氮染料SD1作为取向层,取向层为螺旋轴提供取向方向,并不对螺旋结构进行解旋,在未加外置电压时螺旋结构存在于两基板之间。
4.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,外置电压的极性对应消旋后铁电液晶的指向矢排布方向;施加正向电压时,铁电液晶分子自发偶极矩与电场相互耦合,液晶分子指向矢呈均匀排列,并平行于起偏器透偏方向,此时入射光经过液晶层后偏振态不变,与检偏器透偏方向垂直,是为暗态。
5.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,施加负向电压时,铁电液晶分子自发偶极矩与电场相互耦合,液晶分子指向矢呈均匀排列,并与起偏器透偏方向呈2θ角,此时入射光经过液晶层后偏振态改变,再经检偏器后透射率达最大,是为亮态。
6.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,该液晶光开关采用光敏偶氮染料SD1作为取向层,通过曝光剂量操控取向层的锚定能,其制备方法为:
1)首先将SD1以0.4%的浓度溶于二甲基甲酰胺溶剂中,然后将溶液旋涂在清洁的氧化铟锡玻璃基板上,旋涂层先以800RPM进行5秒预旋转,然后以3000RPM旋转30秒;然后在100℃下进行10分钟的软烘烤,除去SD-1层中的残留溶剂,得到厚度为10nm的SD1膜;
2)将旋涂过SD-1的玻璃基板在偏振UV光下曝光,所述偏振UV光的中心波长为365nm,辐照度I=2mW/cm-2,曝光剂量取18J/cm2。
7.如权利要求1所述的基于电解螺旋型铁电液晶的光开关,其特征在于,所述光开关的响应速度随电压的增加而进一步减小。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201711289580.0A CN108572488B (zh) | 2017-12-08 | 2017-12-08 | 一种基于电解螺旋型铁电液晶的光开关 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201711289580.0A CN108572488B (zh) | 2017-12-08 | 2017-12-08 | 一种基于电解螺旋型铁电液晶的光开关 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN108572488A CN108572488A (zh) | 2018-09-25 |
CN108572488B true CN108572488B (zh) | 2021-07-06 |
Family
ID=63575724
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201711289580.0A Active CN108572488B (zh) | 2017-12-08 | 2017-12-08 | 一种基于电解螺旋型铁电液晶的光开关 |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN108572488B (zh) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1326560A (zh) * | 1998-11-21 | 2001-12-12 | 斯马特显示器株式会社 | 垂直排列螺旋变形液晶显示器 |
JP3267278B2 (ja) * | 1991-09-25 | 2002-03-18 | セイコーエプソン株式会社 | 半導体装置の製造方法 |
CN102768440A (zh) * | 2012-06-30 | 2012-11-07 | 南京大学 | 一种快速响应光开关 |
-
2017
- 2017-12-08 CN CN201711289580.0A patent/CN108572488B/zh active Active
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3267278B2 (ja) * | 1991-09-25 | 2002-03-18 | セイコーエプソン株式会社 | 半導体装置の製造方法 |
CN1326560A (zh) * | 1998-11-21 | 2001-12-12 | 斯马特显示器株式会社 | 垂直排列螺旋变形液晶显示器 |
CN102768440A (zh) * | 2012-06-30 | 2012-11-07 | 南京大学 | 一种快速响应光开关 |
Non-Patent Citations (2)
Title |
---|
Ferroelectric Liquid Crystal Dammann Grating by Patterned Photoalignment;Fan Fan等;《Crystals》;20170306;第1页第1段至第3页第1段 * |
铁电液晶功能器件电路模型的应用研究;王梦遥;《中国博士学位论文全文数据库信息科技辑》;20081231;第6页第1段,第10至13页,图2-2和2-4 * |
Also Published As
Publication number | Publication date |
---|---|
CN108572488A (zh) | 2018-09-25 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Hu et al. | Stable and scalable smart window based on polymer stabilized liquid crystals | |
Du et al. | Electrically tunable liquid crystal terahertz phase shifter driven by transparent polymer electrodes | |
TWI647520B (zh) | 液晶裝置 | |
JP3966517B2 (ja) | 電気光学装置、電気光学的結晶薄膜及びその製造方法 | |
US7102706B2 (en) | Method for aligning polymer network liquid crystal | |
Sharma et al. | Electrically switchable color tags based on active liquid‐crystal plasmonic metasurface platform | |
CA2995131A1 (en) | Lc modulator devices based on non-uniform electrode structures | |
US9939669B2 (en) | Flexible display panel and flexible display | |
KR20010071415A (ko) | 동작중에 전기적으로 스위칭할 수 있는 모드를 가지는스펙트럼 제어가능 반사 편광기 | |
KR102103981B1 (ko) | 백 플로우를 이용한 게스트-호스트 이중 주파수 액정의 스위칭 방법 | |
CN108572487A (zh) | 一种基于铁电液晶光控取向的圆形达曼光栅 | |
Büyüktanir et al. | Flexible bistable smectic-A polymer dispersed liquid crystal display | |
CN108572488B (zh) | 一种基于电解螺旋型铁电液晶的光开关 | |
JP2018508840A (ja) | 3つの透過状態を有する電気光学シャッタ装置を作成するための材料、及びその装置と使用 | |
KR20130064692A (ko) | 전기-광 위상 변조기 | |
Li et al. | 43‐1: Tri‐stable Cholesteric Liquid Crystal Smart Window | |
Lee et al. | A method for improving contrast ratio of polymer dispersed liquid crystal film using the oriented azo-dye molecules in polymer matrix | |
Lin et al. | Dual-frequency liquid-crystal lenses based on a surface-relief dielectric structure on an electrode | |
JP4220810B2 (ja) | 液晶光変調膜の製造方法および液晶光変調膜ならびに液晶光変調器 | |
CN108983457A (zh) | 一种颜色可调谐的液晶彩色滤光片 | |
EP2873712A1 (en) | Polymer stabilized electrically suppressed helix ferroelectric liquid crystal cell | |
CN108957800B (zh) | 一种红外反射器件及其制备方法 | |
Huang et al. | Polarization-dependent optical tuning of focal intensity of liquid crystal polymer microlens array | |
JP2010048907A (ja) | 電圧制御型液晶フィルタを用いた照明装置 | |
CN203773202U (zh) | 一种柔性显示面板和柔性显示器 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |