The extinction ratio is limited by refractive index distortions in the electro-optic crystals that impart wavefront distortion to the optical beam. For these devices, the on:off extinction ratio is typically 50:1 for a 0.5-mm diameter beam. Higher values can be achieved by focusing your beam.

We offer both broadband modulators that can be used at a wide range of frequencies and resonant modulators that operate at a single frequency with much lower drive voltage requirements. The resonant modulators feature a resonant tank circuit to maximize power transfer from driver to crystal, thereby maximizing the voltage across the crystal, lowering required drive voltages. Each resonant phase modulator is built to the your exact specified frequency.

Another common use for an amplitude modulator is as the actuator in an amplitude stabilizer as shown. Here, a photodetector measures a portion of the laser intensity which the servo uses to adjust the transmission of the amplitude modulator. An important consideration in this application is the nonlinear response of the modulator. The changing slope of the modulator's response to input voltage leads to a change in the closed-loop transfer function which could destabilize the feedback loop.