The Quarter Wave Voltage (V_π/2) of a Pockels cell refers to the applied voltage at which the Pockels cell introduces a phase shift of one-quarter of a wavelength (π/2 phase shift) to an incident light beam passing through it. It is typically measured in volts (V).

Similar to the Half Wave Voltage, which induces a phase shift of half a wavelength, the Quarter Wave Voltage is a critical parameter in electro-optic modulation. When the voltage applied to the Pockels cell reaches the quarter-wave voltage, the device can rotate the polarization of the light passing through it by 45 degrees, resulting in a phase shift of one-quarter of a wavelength.

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