CN101995292B - Method and device for measuring electric-optical coefficients of organic polymer thin-film material by utilizing reflection method - Google Patents

Abstract

The invention relates to a characterization technique of an organic polymer electric-optical material, in particular to a method for measuring the electric-optical coefficients of an organic polymer thin-film material by utilizing a reflection method, and a measuring device used by the method, wherein the optical element of the device comprises a single-color optical fiber laser, a collimator, a polarizer, a Soleit-Babinet compensator, an analyzer and a photoelectric detector; and the electric element of the device comprises a direct current/alternating current filter, a phase locking amplifier, a two-way low-frequency signal generator and a computer. The method of the invention adopts a simple and adjustable reflecting light path and combines the electric element with high performance to realize the rapid measurement of the polymer thin-film material. In the invention, the defects of complicated sample manufacture, difficult coupling light path adjustment, incapable loss medium measurement and incapable electric-optical coefficient distribution measurement in the method for directly measuring the electric-optical coefficients are overcome, the invention has the advantages of the direct measurement of the polarized sample, simple adjustment of the light path, and rapid and reliable data treatment, and the distribution of the electric-optical coefficients can be obtained through the measurement for multiple times.

Description

The method and the device of the electrooptical coefficient of reflection method for measuring organic polymer thin film material

Skill wood field

The present invention relates to the characterization technique of organic polymer electrooptical material, the particularly method of the electrooptical coefficient of reflection method for measuring organic polymer thin film material, and the used measurement mechanism of this method.

Background technology

The organic polymer electrooptical material have good processability, can be in different substrates spin-coating film, can be integrated with other electronics, optoelectronic device.The more important thing is that organic polymer material has cutting property, so the refractive index of organic polymer material can regulate and control, and the electro-optical activity of organic polymer material can reach the electrooptical coefficient of the every volt of hundreds of micromicron, be 100 times more than of inorganic material electro-optical activity.Become the most potential material of making low-power, high bandwidth electrooptic modulator.In the manufacturing process of the research and development of new material and high-performance electrooptic modulator, how fast and accurately the electrooptical coefficient of organic polymer material becomes the research focus of numerous researchers after the measurement of polarization.The most directly measuring method is on the electro-optical device of waveguiding structure, directly to add modulation voltage; Utilize coupling process with the laser coupled of TM or TE pattern in the organic polymer sample thin film; Measure the phase shifts of the laser of TM under the modulation voltage effect or TE pattern, thereby calculate the electrooptical coefficient of organic polymer specimen material.The shortcoming of this method is and must the electric light organic polymer material be made waveguiding structure; This just needs selection to be suitable for the organic polymer material of the last under-clad layer of waveguide fabrication technology and polarization; Could accomplish through more than ten steps, organic polymer specimen preparation process is very complicated again.Use the prism-coupled appearance to measure electrooptical coefficient [Yuan Bo, Cao Zhuanqi, the Dou Xiaoming of organic polymer material according to the attenuated total reflection principle.The real-time measurement of polarized polymer thin film electrooptical coefficient.Photoelectric project.Vol.28, No.5,2001:43-47], though simplified the technology of waveguide fabrication; Measure waveguide but need prism that laser coupled is got into, light path is regulated difficulty, and is very high to the film sample quality requirements; Poor repeatability, success ratio are not high, are unfavorable for the research and development of new material.Organic polymer material is made into interferometer, also can measures electrooptical coefficient [Wang Yiping, Chen Jianping, Li Xinwan, Hong Jianxun, Zhang Xiaohong, Zhou Junhe, the Ye Ailun of material.The electrooptical coefficient of optical fiber mach-Ceng Deer interferometric method measurement of polarization polymkeric substance.The optics journal.Vol.25, No.10,2005:1339-1342], but the interferometric method measurement needs the polarization state of control laser in real time, and quite complicated to the adjusting of interfering the arm working point, also want environmental factors such as account temperature, vibration, can't realize fast and convenient measurement.

Summary of the invention

One of the object of the invention is in order to overcome the defective of prior art; Solve the difficulty that is run in the traditional measurement organic polymer thin film materials process; A kind of simple reflected light path that adopted is provided, cooperates the method for electrooptical coefficient of the reflection method for measuring organic polymer thin film material of high performance electricity component.

Two of the object of the invention provides a kind of measurement mechanism of implementing purpose one method.

Method of the present invention is to adopt simple adjustable reflected light path, in conjunction with the high-performance electricity component, realizes the quick measurement of thin polymer film electrooptical coefficient.The present invention overcome that sample making in the direct measurement electrooptical coefficient method is complicated, coupling optical path is regulated difficulty, not energy measurement lossy medium, the shortcoming that distributes of energy measurement electrooptical coefficient not; Sample after the direct measurement of polarization; Light path is regulated simple; The data processing fast and reliable is repeatedly measured the distribution that can obtain electrooptical coefficient.In the polarization condition of optimizing material, making high-performance polymer electrooptic modulator process, can play directive function.

The method of the electrooptical coefficient of reflection method for measuring organic polymer thin film material of the present invention may further comprise the steps:

1) organic polymer soln is spin-coated on the conducting surface of ito glass, forms organic polymer thin film; At the surface sputtering layer of metal conducting film of organic polymer thin film, the conducting surface of ito glass and the metal conductive film of sputter as the upper/lower electrode of organic polymer thin film, are distinguished connection electrode lead-in wire (available conductive adhesive) respectively on upper/lower electrode;

2) with the one-wavelength laser of monochromatic light fibre laser output behind collimating device collimation; Become the line polarisation through the polarizer; And from rope tired-the Babinet compensator transmission after; Shine with miter angle on the nonconductive surface of ito glass of step 1); Incident laser is transmitted on the metal conductive film through the nonconductive surface of ito glass, the conducting surface and the organic polymer thin film of ito glass successively, and transmission laser is reflected by metal conductive film afterwards, passes once more that the nonconductive surface from ito glass penetrates behind the conducting surface of organic polymer thin film, ito glass;

3) from step 2) emergent ray that penetrates of the nonconductive surface of ito glass vertically gets into analyzer, and the direction of shaking thoroughly of analyzer is vertical with the polarizer, and the analyzer emergent ray is received by photodetector;

4) light signal that receives of step 3) photodetector is changed into and is divided into two-way behind the electric signal of direct current and alternating voltage and exports; Wherein one the tunnel be transported to the data collecting card that is installed in computer-internal; Another road is fed through alternating voltage in the lock-in amplifier through the AC/DC wave filter; (1～5V) is input to the reference input mouth of lock-in amplifier, and lock-in amplifier will amplify back output with the alternating voltage that behind the AC/DC wave filter, is transported in the lock-in amplifier with reference to the ac voltage signal same frequency of input with the decay output AC voltage signal of two-way low frequency generator;

5) on two lateral electrodes with the organic polymer thin film sample of the gain output AC voltage signal (20V～250V) be added in step 2 through the conducting surface of ito glass and the contact conductor on the metal conductive film respectively) of the two-way low frequency generator of step 4);

6) recording step 5) be applied to the effective value of the ac voltage signal on organic polymer thin film sample two lateral electrodes; Move rope tired-position of Babinet compensator inner wedge crystal; Simultaneously with being installed in the data collecting card acquisition step 4 of computer-internal) by the d. c. voltage signal with direct current and alternating voltage one tunnel of photodetector output with gather the ac voltage signal of exporting by lock-in amplifier; With computer recording and match DC voltage and alternating voltage curve, calculate the electrooptical coefficient of organic polymer matter sample automatically by computing machine according to the fitting function expression formula;

The collection of the data in the inventive method, processing and calculating are all accomplished processing by the computer program of establishment automatically.

Wherein by the polarizer, rope tired-light path that Babinet compensator, organic polymer matter sample, analyzer etc. are formed in; The polarizer makes the laser that incides in the organic polymer matter sample become linearly polarized light; Two-way low frequency generator gain output voltage signal is added on two lateral electrodes of organic polymer matter sample; Make the organic polymer matter sample after the polarization have the characteristic of uniaxial crystal; Therefore organic polymer matter sample outgoing polarization polarized state of light rotates with respect to the incident light polarization state to some extent, and behind the process analyzer, the rotation of polarization state shows as the variation of transmitted light intensity.Transmitted light intensity I and incident intensity I ₀Relation be:

$\frac{I}{I_0}={\sin }^2\left(\frac{\mathrm{\Γ}}{2}\right)---\left(1\right)$

Wherein Γ is s ripple and the phase differential of p ripple in the organic polymer matter sample, with the two travel path and refractive index relation is arranged.S ripple and p ripple are 2 polarization modes that incident ray polarized light goes out at organic polymer matter sample underexcitation, and s wave polarization state is vertical with plane of incidence, and refractive index is an ordinary refraction index, and p wave polarization attitude is in plane of incidence, and refractive index is unusual optical index.In coordinate system shown in Figure 3, the refractive index of incident ray polarized light in the organic polymer matter sample satisfies ellipsoid equation, n _x, n _y, n _zBe respectively the intersection point of ellipsoid and x, y, z coordinate axis, the z axle is an optical axis direction, the s ripple in the xoy plane, the p ripple in the xoz plane, with the angle of z axle be α, the refractive index n that s ripple and p ripple are corresponding _sAnd n _pBe respectively:

n _s＝n _y (2)

$\frac{1}{{\mathrm{<figure-callout\; id="2"\; label="n\; p"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">n</figure-callout>}}_p^{}}=\frac{{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&alpha;}}{n_x^2}+\frac{{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\mathrm{\&alpha;}}{n_z^2}---\left(3\right)$

Apply the electric field that electric field intensity is E (being the gain output AC voltage of two-way low frequency generator) along the z direction of principal axis, cause the variations in refractive index δ n of s ripple and p ripple by electrooptical effect _sWith δ n _pBe respectively:

δn _s＝δn _y (4)

$\mathrm{\&delta;}{n}_p=\frac{{\sin }^2\mathrm{\&theta;}}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}\mathrm{\&delta;}{n}_z+\frac{n^2-{\sin }^2\mathrm{\&theta;}}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}\mathrm{\&delta;}{n}_x---\left(5\right)$

And $\mathrm{\&delta;}{n}_x=\mathrm{\&delta;}{n}_y=\frac{1}{2}{r}_{13}{\mathrm{En}}^3,$ $\mathrm{\&delta;}{n}_z=\frac{1}{2}{r}_{33}{\mathrm{En}}^3,$ R wherein ₁₃And r ₃₃Be respectively the electrooptical coefficient on x axle, the z direction of principal axis, E is an electric field intensity, and n is not for adding the organic polymer matter sample refractive index before the modulation voltage, and θ is the incident angle of laser at the ito glass nonconductive surface, satisfies refraction law with α, sin θ=nsin α.

Consider the difference of propagation path simultaneously, the phase differential of s ripple and p ripple is in the organic polymer matter sample that modulated electric fields E causes:

$\mathrm{\&Gamma;}=\frac{2\mathrm{\&pi;}{\mathrm{<figure-callout\; id="2"\; label="dn"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">dn</figure-callout>}}^2{\sin }^2\mathrm{\&theta;}}{\mathrm{\&lambda;}\sqrt{n^2-{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\mathrm{\&theta;}}}E(r_{33}-r_{13})---\left(6\right)$

D is the organic polymer sample thickness in the formula, and n is not for adding the organic polymer matter sample refractive index before the modulation voltage, and θ is the incident angle of laser at the ito glass nonconductive surface, and λ is an optical maser wavelength, and E is an electric field intensity, r ₁₃And r ₃₃Being respectively the electrooptical coefficient on x axle, the z direction of principal axis, is the basic parameter of polar polymer material.Consider r ₃₃=3r ₁₃, obtain the expression formula of phase differential and electrooptical coefficient behind the following formula abbreviation.

In the measurement, the transmitted light intensity that the alternating voltage that applies on the organic polymer matter sample causes changes very little, must just can detect through frequency lock by means of lock-in amplifier.Change organic polymer matter sample provinculum tired-Babinet compensator in the position of cumeat, can change the polarization state that incides organic polymer matter sample laser.Under a certain special polarization state, the phase differential of s ripple and p ripple is a pi/2, and transmitted light intensity is a half of incident intensity, and the transmitted light intensity that modulation voltage causes changes maximum, and this moment, the output voltage of lock-in amplifier was a maximum amplitude, and satisfied:

$\frac{I_{\mathrm{AC}}}{I_{\mathrm{DC}}/2}=\mathrm{\&Gamma;}---\left(7\right)$

In the formula, I _ACBe the maximum amplitude of lock-in amplifier output voltage, I _DCFor rope tired-Babinet compensator in cumeat move and produce the maximum amplitude that light intensity changes.With formula (6) substitution formula (7), substitution voltage V=Ed (V is the effective value of the alternating voltage that adds on the organic polymer matter sample, and E is an electric field intensity, and d is the organic polymer sample thickness), the computing formula that obtains electrooptical coefficient after the arrangement is:

$r_{33}=\frac{3\mathrm{\&lambda;}\sqrt{n^2-{\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">sin</figure-callout>}}^2\mathrm{\&theta;}}}{2\mathrm{\&pi;}{\mathrm{<figure-callout\; id="2"\; label="Vn"\; filenames="H2009100914168E00011.png"\; state="\{\{state\}\}">Vn</figure-callout>}}^2{\sin }^2\mathrm{\&theta;}}\&CenterDot;\frac{I_{\mathrm{AC}}}{I_{\mathrm{DC}}}---\left(8\right)$

Measuring method of the present invention is applicable to the polarization organic polymer thin film material with electro-optical activity.

Described polarization organic polymer material with electro-optical activity is to contain the chromophoric organic polymer material of function.

The thickness of described metal conductive film is 20～200nm; The different metallic conducting membrane material has different conducting film thickness, and when adopting the aluminium film, thickness is that 30nm gets final product, as when adopting golden film, thickness is that 100nm gets final product.

Described metal is the metals such as gold, silver, aluminium or copper with high electrical conductivity.

The measurement mechanism of the electrooptical coefficient that is used for reflection method for measuring organic polymer thin film material of the present invention is as shown in Figure 1, optical element wherein comprise monochromatic light fibre laser, collimating apparatus, the polarizer, rope tired-Babinet compensator, analyzer and photodetector; Electricity component comprises AC/DC wave filter, lock-in amplifier, two-way low frequency generator and computing machine.

Light path the place ahead at the monochromatic light fibre laser is equipped with collimating apparatus, in light path the place ahead of collimating apparatus the polarizer is installed, be equipped with in light path the place ahead of the polarizer rope tired-Babinet compensator, rope tired-light path the place ahead of Babinet compensator is equipped with ito glass;

Wherein, the nonconductive surface of described ito glass facing to rope tired-emergent light of Babinet compensator, and the nonconductive surface of ito glass tire out with rope-emitting light path of Babinet compensator becomes miter angle; Conducting surface at ito glass scribbles organic polymer thin film, on the surface of organic polymer thin film the layer of metal conducting film is arranged, and the conducting surface of ito glass and metal conductive film are connected with contact conductor (available conducting resinl is stained with) respectively.

On the vertical optical path of the emergent light of the nonconductive surface of ito glass, analyzer is installed; Light path the place ahead at analyzer is equipped with photodetector, and the output signal outlet of photodetector is connected with the signal input port of the data collecting card of AC/DC wave filter and computer-internal respectively through cable.

The signal outlet of described AC/DC wave filter is connected with the voltage signal inlet of lock-in amplifier through cable; The decay output voltage outlet of two-way low frequency generator links to each other with the reference input mouth of lock-in amplifier through cable, and the signal outlet of lock-in amplifier is connected through the signal input port of cable with the data collecting card of computer-internal.

The gain output voltage outlet of described two-way low frequency generator is connected with the conducting surface of ito glass and the contact conductor of metal conductive film respectively through lead.

The used various elements of the present invention are the commercially available prod, wherein:

Described rope is tired-and Babinet compensator has electric screw, is electronic compensator.

Described photodetector inside has biasing circuit; The BNC connector output of anode current through panel, output port comprised simultaneously d. c. voltage signal (rope is tired-Babinet compensator in cumeat move the change in optical signal that causes) and ac voltage signal (change in optical signal that the modulated electric fields that organic polymer matter sample both sides apply causes).

Described two-way low frequency signal is freeed utensil has the two-way synchronization output signal, and one the tunnel is gain signal, and as the ac voltage signal that is applied on the organic polymer matter sample, the one tunnel is deamplification, as the reference signal of lock-in amplifier.

The present invention has following advantage:

1. sample making is simple; Need not carry out the making processing of waveguiding structure to organic polymer material to be measured; Only need the organic polymer material spin coating is become film like, can test after polarizing then at once, be very beneficial for judging fast the quality of electric light organic polymer material performance.

2. only need a spot of light path to regulate, the whole test process automaticity is high, and is easy to be reliable;

3. utilize data collecting card with last measurement result input computing machine, improved data processing speed and computational accuracy, be convenient to preserve data, more different result;

4. change the position of testing sample slightly, can measure the electrooptical coefficient of the zones of different on the sample, understand the distribution of the electro-optical activity of whole sample.

Description of drawings

Fig. 1. measurement mechanism synoptic diagram of the present invention.

Fig. 2. show the measurement mechanism synoptic diagram of the present invention of the mobile direction of optical propagation direction and electric signal; Wherein: dotted line is represented the direction that light is propagated; Solid line is represented the flow direction of electric signal.

Fig. 3. the index ellipsoid synoptic diagram of polarization back organic polymer matter sample.

Reference numeral

1. monochromatic light fibre laser 2. collimating apparatuss 3. polarizers

4. rope tires out-Babinet compensator 5. organic polymer matter samples 6. analyzers

7. photodetector 8. AC/DC wave filters 9. lock-in amplifiers

10. two-way low frequency generator 11. computing machines

Embodiment 1

See also Fig. 1.The optical element of measurement mechanism that is used for the electrooptical coefficient of reflection method for measuring organic polymer thin film material comprise monochromatic light fibre laser 1, collimating apparatus 2, the polarizer 3, rope tired-Babinet compensator 4, analyzer 6 and photodetector 7; Electricity component comprises AC/DC wave filter 8, lock-in amplifier 9, two-way low frequency generator 10 and computing machine 11.

Light path the place ahead at monochromatic light fibre laser 1 is equipped with collimating apparatus 2; Light path the place ahead in collimating apparatus 2 is equipped with the polarizer 3; Be equipped with in light path the place ahead of the polarizer 3 rope tired-Babinet compensator 4, rope tired-light path the place ahead of Babinet compensator 4 is equipped with ito glass;

Wherein, the nonconductive surface of described ito glass facing to rope tired-emergent light of Babinet compensator 4, and the nonconductive surface of ito glass tire out with rope-emitting light path of Babinet compensator 4 becomes miter angle; Conducting surface at ito glass scribbles organic polymer matter sample 5 films, on the surface of organic polymer sample thin film the layer of metal conducting film is arranged, and the conducting surface and the metal conductive film of ito glass have contact conductor with conductive adhesive respectively.

On the vertical optical path of the emergent light of the nonconductive surface of ito glass, analyzer 6 is installed; Light path the place ahead at analyzer 6 is equipped with photodetector 7, and the output signal outlet of photodetector 7 is connected with the signal input port of AC/DC wave filter 8 with the data collecting card of computing machine 11 inside respectively through cable.

The signal outlet of described AC/DC wave filter 8 is connected with the voltage signal inlet of lock-in amplifier 9 through cable; The decay output voltage outlet of two-way low frequency generator 10 links to each other with the reference input mouth of lock-in amplifier through cable, and the signal outlet of lock-in amplifier 9 is connected through the signal input port of cable with the data collecting card of computing machine 11 inside.

The gain output voltage outlet of described two-way low frequency generator 10 is connected with the conducting surface of ito glass and the contact conductor of metal conductive film respectively through lead.

When utilizing said apparatus to be used for the electrooptical coefficient of reflection method for measuring organic polymer thin film material; The light of monochromatic light fibre laser output becomes linearly polarized light after through collimating apparatus, the polarizer, its polarization state successively by rope tired-Babinet compensator rotates with organic polymer matter sample under the modulated electric fields effect.Photodetector changes the light signal that receives into and is divided into two-way behind the electric signal of direct current and alternating voltage and exports; Wherein one the tunnel be transported to the data collecting card that is installed in computer-internal; Another road is fed through filter amplifying processing in the lock-in amplifier through the AC/DC wave filter with alternating voltage; Adopt the two-way low frequency generator in the system; Output two-way synchronizing signal; One the tunnel is to export after the ac voltage signal amplitude that oscillator produces is amplified several times; Be called gain output AC voltage signal, the one tunnel is to export behind the ac voltage signal amplitude fading that oscillator is produced, and is called decay output AC voltage signal; Gain output AC voltage signal (20V～250V) be input on the contact conductor of organic polymer thin film with the two-way low frequency generator; To decay, (1～5V) is input to the reference input mouth of lock-in amplifier to the output AC voltage signal, and lock-in amplifier will amplify back output with the alternating voltage that behind the AC/DC wave filter, is transported in the lock-in amplifier with reference to the ac voltage signal same frequency of importing; The ac voltage signal of the d. c. voltage signal of photodetector output and lock-in amplifier output is by the data collecting card collection of computer-internal; Computer recording and match DC voltage and alternating voltage curve can be gone out the electrooptical coefficient of organic polymer matter sample by COMPUTER CALCULATION according to the fitting function expression formula.The collection of data, processing and calculating are all accomplished processing by the computer program of establishment automatically.

Can find out optical propagation direction and the electric signal direction that flows by Fig. 2, dotted line representes that direction solid line that light is propagated representes the flow direction of electric signal.

Embodiment 2

Utilize the measurement mechanism of embodiment 1 below, come with the electrooptical coefficient of the methyl methacrylate film of doping chromophore I after the measurement of polarization that further the present invention will be described.

Chromophore I has following structure:

1) is doped in methyl methacrylate with 10% mass ratio chromophore I and is dissolved in the cyclopentane; The mass concentration that obtains solution is 10%, fully after the dissolving, the solution for preparing is spin-coated on the conducting surface of ito glass; The about 1.5 μ m of thickness added the 10000V electric polarization 30 minutes under 80 ℃.The polarization back gold about film surface sputter 100nm is as top electrode, on the conducting surface of ito glass and gold electrode, uses the conductive adhesive contact conductor;

2) with the monochromatic infrared laser of 1310nm fiber laser output behind collimating device collimation; Become the line polarisation through the polarizer; And from rope tired-the Babinet compensator transmission after; Shine with miter angle on the nonconductive surface of ito glass of step 1); Incident laser is transmitted on the golden conducting film through the conducting surface of the nonconductive surface of ito glass, ito glass and the methyl methacrylate film that contains chromophore I successively, and transmission laser is reflected by golden conducting film afterwards, passes once more that the nonconductive surface from ito glass penetrates behind the conducting surface of the methyl methacrylate film that contains chromophore I, ito glass;

3) from step 2) emergent ray that penetrates of the nonconductive surface of ito glass vertically gets into analyzer, and the direction of shaking thoroughly of analyzer is vertical with the polarizer, and the analyzer emergent ray is received by photodetector;

4) light signal that receives of step 3) photodetector is changed into and is divided into two-way behind the electric signal of direct current and alternating voltage and exports; Wherein one the tunnel be transported to the data collecting card that is installed in computer-internal; Another road is fed through alternating voltage in the lock-in amplifier through the AC/DC wave filter; Decay output AC voltage (effective value 4V) signal of two-way low frequency generator is input to the reference input mouth of lock-in amplifier, and lock-in amplifier will amplify back output with the alternating voltage that behind the AC/DC wave filter, is transported in the lock-in amplifier with reference to the ac voltage signal same frequency of input;

5) gain output AC voltage (peak-to-peak value 120V) signal with the two-way low frequency generator of step 4) is added in step 2 through the conducting surface of ito glass and the contact conductor on the golden conducting film respectively) two lateral electrodes of the methyl methacrylate film sample that contains chromophore I on;

6) recording step 5) be applied to the effective value of the ac voltage signal on methyl methacrylate film sample two lateral electrodes that contain chromophore I; Move rope tired-position of Babinet compensator inner wedge crystal; Simultaneously with being installed in the data collecting card acquisition step 4 of computer-internal) by the d. c. voltage signal with direct current and alternating voltage one tunnel of photodetector output with gather the ac voltage signal of exporting by lock-in amplifier; Output voltage curve with the Labview program record data capture card of writing; With sine function match DC voltage and alternating voltage curve; According to the fitting function expression formula, the electrooptical coefficient that is calculated the methyl methacrylate sample that contains chromophore I by computing machine automatically is 4.56pm/V.The spot measurement time is about 5 minutes, and measurement result can repeat in 4 months.Change the incoming position of laser on sample, can record the methyl methacrylate sample polarization electrooptical coefficient that contains chromophore I and distribute.

Embodiment 3

Utilize the measurement mechanism of embodiment 1 below, come with the electrooptical coefficient of the polycarbonate film of doping chromophore II after the measurement of polarization that further the present invention will be described.

Chromophore II has following structure:

1) chromophore II is doped in the polycarbonate with 11% mass ratio, using cyclopentanone to be made into mass percent concentration is 20% polymer solution, fully after the dissolving, the solution for preparing is spin-coated on the conducting surface of ito glass, the about 3 μ m of thickness.Place high-voltage electric field to polarize film, the polarization temperature is 140 ℃, and polarizing voltage is 90～110V/ μ m, and the polarization time is 30 minutes.The polarization back gold about film surface sputter 100nm is as top electrode, on the conducting surface of ito glass and gold electrode, uses the conductive adhesive contact conductor;

2) with the monochromatic infrared laser of 1310nm fiber laser output behind collimating device collimation; Become the line polarisation through the polarizer; And from rope tired-the Babinet compensator transmission after; Shine with miter angle on the nonconductive surface of ito glass of step 1); Incident laser is transmitted on the golden conducting film through the nonconductive surface of ito glass, the conducting surface of ito glass and the polycarbonate film of doping chromophore II successively, and transmission laser is reflected by golden conducting film afterwards, passes once more that the nonconductive surface from ito glass penetrates behind the conducting surface of polycarbonate film, ito glass of doping chromophore II;

3) from step 2) emergent ray that penetrates of the nonconductive surface of ito glass vertically gets into analyzer, and the direction of shaking thoroughly of analyzer is vertical with the polarizer, and the analyzer emergent ray is received by photodetector;

4) light signal that receives of step 3) photodetector is changed into and is divided into two-way behind the electric signal of direct current and alternating voltage and exports; Wherein one the tunnel be transported to the data collecting card that is installed in computer-internal; Another road is fed through alternating voltage in the lock-in amplifier through the AC/DC wave filter; Decay output AC voltage (effective value 4V) signal of two-way low frequency generator is input to the reference input mouth of lock-in amplifier, and lock-in amplifier will amplify back output with the alternating voltage that behind the AC/DC wave filter, is transported in the lock-in amplifier with reference to the ac voltage signal same frequency of input;

5) gain output AC voltage (peak-to-peak value 120V) signal with the two-way low frequency generator of step 4) is added in step 2 through the conducting surface of ito glass and the contact conductor on the golden conducting film respectively) two lateral electrodes of polycarbonate film sample of doping chromophore II on;

6) recording step 5) be applied to the effective value of the ac voltage signal on polycarbonate film sample two lateral electrodes of doping chromophore II; Move rope tired-position of Babinet compensator inner wedge crystal; Simultaneously with being installed in the data collecting card acquisition step 4 of computer-internal) by the d. c. voltage signal with direct current and alternating voltage one tunnel of photodetector output with gather the ac voltage signal of exporting by lock-in amplifier; Output voltage curve with the Labview program record data capture card of writing; With sine function match DC voltage and alternating voltage curve; According to the fitting function expression formula, the electrooptical coefficient that is calculated the polycarbonate sample of doping chromophore II by computing machine automatically is 5.2pm/V.The spot measurement time is about 5 minutes, and measurement result can repeat in 4 months.Change the incoming position of laser on sample, the polycarbonate sample polarization electrooptical coefficient that can record doping chromophore II distributes.

Claims (10)

1. the method for the electrooptical coefficient of a reflection method for measuring organic polymer thin film material is characterized in that, this method may further comprise the steps:

1) organic polymer soln is spin-coated on the conducting surface of ito glass, forms organic polymer thin film; At the surface sputtering layer of metal conducting film of organic polymer thin film, as the upper/lower electrode of organic polymer thin film, connection electrode goes between respectively on upper/lower electrode respectively for the conducting surface of ito glass and the metal conductive film of sputter;

2) with the one-wavelength laser of monochromatic light fibre laser output behind collimating device collimation; Become the line polarisation through the polarizer; And from the rope that has electric screw tired-the Babinet compensator transmission after; Shine with miter angle on the nonconductive surface of ito glass of step 1); Incident laser is transmitted on the metal conductive film through the nonconductive surface of ito glass, the conducting surface and the organic polymer thin film of ito glass successively, and transmission laser is reflected by metal conductive film afterwards, passes once more that the nonconductive surface from ito glass penetrates behind the conducting surface of organic polymer thin film, ito glass;

3) from step 2) emergent ray that penetrates of the nonconductive surface of ito glass vertically gets into analyzer, and the direction of shaking thoroughly of analyzer is vertical with the polarizer, and the analyzer emergent ray is received by photodetector;

4) light signal that receives of step 3) photodetector is changed into and is divided into two-way behind the electric signal of direct current and alternating voltage and exports; Wherein one the tunnel be transported to the data collecting card that is installed in computer-internal; Another road is fed through alternating voltage in the lock-in amplifier through the AC/DC wave filter; The decay output AC voltage signal of two-way low frequency generator is input to the reference input mouth of lock-in amplifier, and lock-in amplifier will amplify back output with the alternating voltage that behind the AC/DC wave filter, is transported in the lock-in amplifier with reference to the ac voltage signal same frequency of input;

5) the gain output AC voltage signal with the two-way low frequency generator of step 4) is added in step 2 through the conducting surface of ito glass and the contact conductor on the metal conductive film respectively) two lateral electrodes of organic polymer thin film sample on;

6) recording step 5) be applied to the effective value of the ac voltage signal on organic polymer thin film sample two lateral electrodes; Move the rope have electric screw tired-position of Babinet compensator inner wedge crystal; Simultaneously with being installed in the data collecting card acquisition step 4 of computer-internal) by the d. c. voltage signal with direct current and alternating voltage one tunnel of photodetector output with gather the ac voltage signal of exporting by lock-in amplifier; With computer recording and match DC voltage and alternating voltage curve, calculate the electrooptical coefficient of organic polymer matter sample automatically by computing machine according to the fitting function expression formula;

Described organic polymer is the polarization organic polymer material with electro-optical activity.

2. method according to claim 1 is characterized in that: the thickness of described metal conductive film is 20～200nm.

3. method according to claim 1 and 2 is characterized in that: described metal is gold, silver, aluminium or the copper metal with high electrical conductivity.

4. method according to claim 1 is characterized in that: described polarization organic polymer material with electro-optical activity is to have the chromophoric polar polymer material of function.

5. method according to claim 1 is characterized in that: the decay output AC voltage of described two-way low frequency generator is 1～5V;

The gain output AC voltage of described two-way low frequency generator is 20V～250V.

6. the rope that measurement mechanism that is used for the electrooptical coefficient of reflection method for measuring organic polymer thin film material, optical element wherein comprise monochromatic light fibre laser, collimating apparatus, the polarizer, have an electric screw is tired-Babinet compensator, analyzer and photodetector; Electricity component comprises AC/DC wave filter, lock-in amplifier, two-way low frequency generator and computing machine, it is characterized in that:

Light path the place ahead at the monochromatic light fibre laser is equipped with collimating apparatus; Light path the place ahead in collimating apparatus is equipped with the polarizer; Be equipped with in light path the place ahead of the polarizer the rope that has electric screw tired-Babinet compensator, the rope that has electric screw tired-light path the place ahead of Babinet compensator is equipped with ito glass;

Wherein, the nonconductive surface of described ito glass facing to the rope that has electric screw tired-emergent light of Babinet compensator, and the nonconductive surface of ito glass tire out with the rope that has electric screw-emitting light path of Babinet compensator becomes miter angle; Conducting surface at ito glass scribbles organic polymer thin film, on the surface of organic polymer thin film the layer of metal conducting film is arranged, and the conducting surface of ito glass and metal conductive film are connected with contact conductor respectively;

On the vertical optical path of the emergent light of the nonconductive surface of ito glass, analyzer is installed; Light path the place ahead at analyzer is equipped with photodetector, and the output signal outlet of photodetector is connected with the signal input port of the data collecting card of AC/DC wave filter and computer-internal respectively through cable;

The signal outlet of described AC/DC wave filter is connected with the voltage signal inlet of lock-in amplifier through cable; The decay output voltage outlet of two-way low frequency generator links to each other with the reference input mouth of lock-in amplifier through cable, and the signal outlet of lock-in amplifier is connected through the signal input port of cable with the data collecting card of computer-internal;

The gain output voltage outlet of described two-way low frequency generator is connected with the conducting surface of ito glass and the contact conductor of metal conductive film respectively through lead.

7. measurement mechanism according to claim 1 is characterized in that: the thickness of described metal conductive film is 20～200nm.

8. according to claim 6 or 7 described measurement mechanisms, it is characterized in that: described metal is gold, silver, aluminium or the copper metal with high electrical conductivity.

9. measurement mechanism according to claim 1 is characterized in that: described organic polymer is the polarization organic polymer material with electro-optical activity.

10. measurement mechanism according to claim 9 is characterized in that: described polarization organic polymer material with electro-optical activity is to have the chromophoric polymeric material of function.

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