Performance analysis of DKDP electro-optic modulators in the presence of piezoelectric coupling

Abstract

Electro-optic crystals suffer can suffer from piezo-electric ringing, a phenomenon that can degrade the efficiency of the device. Piezo-electric ringing is a coupling of the elasto-optic and piezo-electric effects and can be detrimental when the modulation frequency excites the acoustic modes of the crystal. This mechanical phenomenon is also highly dependent on the geometry and physical properties of the crystal. The piezo-electric ringing stress waves are complex, but can be modeled using a dynamic Finite Element Analysis (FEA) simulation of the crystal and a simple beam propagation simulation. This model can produce accurate results with proper material and modulation parameters. In this effort, the piezoelectric response of a Deuterated Dihydrogen Potassium Phosphate (DKDP) crystal is analyzed. The simulation results are then compared to experimental results to demonstrate model accuracy. This method can be used on other electro-optic crystals.