Teng-Man Method

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Teng-Mann Method for Measuring Electro-optic coefficient

Teng-Man Testing configuration

We use the Teng - Man method to measure R33. R33 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 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_Mann techniques allows real-time optimization of processing conditions because you can evaluate r33 during the poling process.



See Khanarian 1996 [1]

See STC-MDITR research project 1.1 [2]

Technique

video to come

Significance

References

  1. Khanarian, et. al., JOSA B13, 1927 (1996)
  2. http://stc-mditr.org/research/oeoaomd/projects/1.111.cfm Measuring R33 with Interferometry