Voltage controlled-bandwidth electrooptic transverse phase modulator with parallel electrodes

Abstract EN

An algorithm to find the bandwidth (ΔF) and half wave retardation (V±π) of the transverse phase modulator for several electrooptic materials with X, Y and Z-cuts, is cast where ΔF and V±π are calculated by determining the propagation constant of anisotropic metal clad electrooptic rectangular waveguide before (βo) and after (βv) applied voltage through parallel electrodes.

The optimum design with broad ΔF, lower V±π and smallest propagation losses is done.

It is found that KNbO3 without rotating of axes (Z-cut) is the best material but, BaTiO5 with rotating of axes (Y-cut) gives smallest figure of merit (Vπ/ΔF).

The values of ΔF, V±π and Vπ/ΔF are increased with the operating wavelength (λ).

The propagation constant approximately, is independent of the electrode material and silver gives smallest losses.

Either E x or E y give similar numerical results with exchange the orientation cases.

The effect of modulator length can be treated by change the applied voltage with the same reciprocal ratio without rotating of axes.