Teng-Man Method

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>

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

Data from Teng-Mann measurement

Teng_Mann techniques allows real-time optimization of processing conditions because you can evaluate r₃₃ during the poling process.

Real time optimization of r₃₃

See Khanarian 1996

See STC-MDITR research project 1.1 Measuring R33 with Interferometry

Technique

video to come