Electrooptical modulator

[poonam devi]

hello,
if i want to design a simple longitudinal electro optic phase modulator in OPTI-BPM, how i will give a input signal and how i will draw electrode region. i am attaching design, what i want to design.

[Steve Dods]

The Beam Propagation Method (BPM) is most effective for the analysis of optical waveguides. The electro optic effect is very small for most materials, it requires propagation over thousands of wavengths to have any measurable effect. I don’t see waveguides in the attached sketch and therefore doubt that OptiBPM could be applied.

[poonam devi]

sir, i am attaching another design please check it.

[Steve Dods]

TThe electrooptic effect for most materials is very small, on the order of 10^ -12 [V/m]. It can be significant if the electric field is applied at close range to the electrodes. The effect on phase can be significant if the electric field is applied over a long distance of propagation. This is the reason OptiBPM expects the electric field will be made by electrodes in the transverse plane, and will follow the propagation so that the eo effect can accumulate as it propagates. OptiBPM follows these design rules. OptiBPM can usually simulate most EO phase modulators that follow the above design rules.
The attached sketch shows application of the electrostatic field over the length of propagation, but the electrodes are as far apart as the length of propagation. The resulting electric field and EO effect will be preduced. I fear the modulation of the phase will be so small it cannot be measured.

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