Difference between revisions of "Teng-Man Method"

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(New page: === Teng-Mann Method for Measuring Electro-optic coefficient=== thumb|400px|Teng-Man Testing configuration We use the Teng - Man method to measure R<sub>33</sub...)
 
 
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=== Teng-Mann Method for Measuring Electro-optic coefficient===
<table id="toc" style="width: 100%">
[[Image:Tang_mann_r33.png|thumb|400px|Teng-Man Testing configuration]]
<tr>
We use the Teng - Man method to measure R<sub>33</sub>.
<td style="text-align: center; width: 33%">[[Main_Page#Research Equipment, Devices and Techniques|Return to Research Tool Menu]]</td>
R<sub>33</sub> is an elipsometric measurement. You apply a voltage to the film while making the elipsometric measurements and looking for changes in the signal. You have to be careful with the kind of glass and the kind of tin oxide that is used. These measurements are made with the materials in a device configuration. The formula for R<sub>33</sub>
=== Teng-Man Method for Measuring Electro-optic coefficient===
[[Image:teng_mann.png|thumb|500px|Teng-Man Testing configuration]]
The Teng - Man method can measure R<sub>33</sub> as the sample is being poled.
R<sub>33</sub> is an elipsometric measurement<ref>http://en.wikipedia.org/wiki/Ellipsometry</ref><ref>SIMPLE REFLECTION TECHNIQUE FOR MEASURING THE ELECTRO-OPTIC COEFFICIENT OF POLED POLYMERS Teng CC, Man, HT APPLIED PHYSICS LETTERS  Volume: 56  Issue: 18  Pages: 1734-1736  DOI: 10.1063/1.103107</ref> . A poling voltage is applied to the film while making the elipsometric measurements and looking for changes in the AC signal generated by incident light. The stage can be heated until the film reaches its melting point T<sub>g</sub>. These measurements are made with the materials in a device configuration. The formula for R<sub>33</sub>


:<math>r_{33}= \frac {3\lambda I_m (n^2 - sin^2 \theta) ^{1/2}} {4 \pi V_{poly}I_c n^2 sin^2 \theta}
:<math>r_{33}= \frac {3\lambda I_m } {4 \pi V_{poly}I_c n^2 } \frac {(n^2 - sin^2 \theta) ^{1/2}}{sin^2 \theta} \approx I_m/ I_c
\,\!</math>
\,\!</math>
where
where
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:<math>V_{poly}= V_{ACtot}  \frac {d_{poly}}  {d_{poly} + d_{clad}}  \cdot \sqrt {\frac {\epsilon_{clad}} {\epsilon _{poly}}}\,\!</math>
:<math>V_{poly}= V_{ACtot}  \frac {d_{poly}}  {d_{poly} + d_{clad}}  \cdot \sqrt {\frac {\epsilon_{clad}} {\epsilon _{poly}}}\,\!</math>
<br clear='all'>


[[Image:Teng_mann_data.png|thumb|500px|Data from Teng-Mann measurement]]


The measured quanitities are:
:<math>I= 2I_M\,\!</math> Modulated Intensity
:<math>I_0 = 2I_C\,\!</math>  Output intensity
:<math>V_m = V_0 sin\omega t\,\!</math> Modulation Voltage


<br clear='all'>
[[Image:Teng mann graph.png|thumb|400px|right|Real time optimization of r<sub>33</sub>]]
Teng-Man techniques allows real-time optimization of processing conditions because you can evaluate r<sub>33</sub> during the poling process. It is used to confirm that a sample has been poled. The R33 measurement is best used as a relative measure because it can be inaccurate. Use attenuated total reflection ATR to get an accurate absolute measure.
<br clear='all'>
See Khanarian 1996 <ref>Khanarian, et. al., JOSA B13, 1927 (1996)</ref>
See Khanarian 1996 <ref>Khanarian, et. al., JOSA B13, 1927 (1996)</ref>


See STC-MDITR research project 1.1 [http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry]
See STC-MDITR research project 1.1 <ref>http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry</ref>
<br clear='all'>
 
=== Technique ===
{{#ev:youtube|FjjnY77ypNc}}
 
=== Significance ===
 
 
 
=== References ===
<references/>

Latest revision as of 16:40, 2 November 2016

Teng-Man Method for Measuring Electro-optic coefficient

Teng-Man Testing configuration

The Teng - Man method can measure R33 as the sample is being poled. R33 is an elipsometric measurement[1][2] . A poling voltage is applied to the film while making the elipsometric measurements and looking for changes in the AC signal generated by incident light. The stage can be heated until the film reaches its melting point Tg. These measurements are made with the materials in a device configuration. The formula for R33

<math>r_{33}= \frac {3\lambda I_m } {4 \pi V_{poly}I_c n^2 } \frac {(n^2 - sin^2 \theta) ^{1/2}}{sin^2 \theta} \approx I_m/ I_c

\,\!</math> where

<math>I_m\,\!</math> is the amplitude of modulation
<math>V_{poly}\,\!</math> is the modulation voltage across EO polymer
<math>I_c\,\!</math> is the half intensity point
<math>n\,\!</math> is the refractive index of the polymer

and

<math>V_{poly}= V_{ACtot} \frac {d_{poly}} {d_{poly} + d_{clad}} \cdot \sqrt {\frac {\epsilon_{clad}} {\epsilon _{poly}}}\,\!</math>


Data from Teng-Mann measurement

The measured quanitities are:

<math>I= 2I_M\,\!</math> Modulated Intensity
<math>I_0 = 2I_C\,\!</math> Output intensity
<math>V_m = V_0 sin\omega t\,\!</math> Modulation Voltage


Real time optimization of r33

Teng-Man techniques allows real-time optimization of processing conditions because you can evaluate r33 during the poling process. It is used to confirm that a sample has been poled. The R33 measurement is best used as a relative measure because it can be inaccurate. Use attenuated total reflection ATR to get an accurate absolute measure.



See Khanarian 1996 [3]

See STC-MDITR research project 1.1 [4]

Technique

Significance

References

  1. ↑ http://en.wikipedia.org/wiki/Ellipsometry
  2. ↑ SIMPLE REFLECTION TECHNIQUE FOR MEASURING THE ELECTRO-OPTIC COEFFICIENT OF POLED POLYMERS Teng CC, Man, HT APPLIED PHYSICS LETTERS Volume: 56 Issue: 18 Pages: 1734-1736 DOI: 10.1063/1.103107
  3. ↑ Khanarian, et. al., JOSA B13, 1927 (1996)
  4. ↑ http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry
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