Pockels effect

[1][2] The non-linear counterpart, the Kerr effect, causes changes in the refractive index at a rate proportional to the square of the applied electric field.

In optical media, the Pockels effect causes changes in birefringence that vary in proportion to the strength of the applied electric field.

KD*P or DKDP), lithium niobate (LiNbO3), beta-barium borate (BBO), barium titanate (BTO) and in other non-centrosymmetric media such as electric-field poled polymers or glasses.

[3] The key component of a Pockels cell is a non-centrosymmetric single crystal with an optic axis whose refractive index is controlled by an external electric field.

By controlling the refractive index, the optical retardance of the crystal is altered so the polarization state of incident light beam is changed.

Longitudinal Pockels cells operate with electric field applied along the crystal optic axis or along incident beam propagation.

A transverse Pockels cell that uses a KDP (or one of its isomorphs) consists of two crystals in opposite orientation, which together give a zero-order waveplate when the voltage is turned off.

Pockels cells for fiber optics may employ a traveling wave design to reduce current requirements and increase speed.

Due to the growing of the polarized volume the electric field in the crystal in front of the wave increases linearly, or the driver has to provide a constant current leakage.

A Pockels cell, by design, is a capacitor, and often require high voltages to change the state of the polarization of the laser beam to effectively operate as a switchable waveplate.

Pockels cell drivers provide this high voltage in the form of very fast pulses, which typically have rise times of less than 10 nanoseconds.

When the gain medium has the desired population inversion, the Pockels cell is switched "open", and a short high energy laser pulse is created.

Light from an argon-ion laser was passed through the Pockels cell to create pulse modulations corresponding to the original FM video and audio signals to be recorded on the master videodisc.

The DRAW system was originally preferred, since it didn't require clean-room conditions during disc recording and allowed instant quality checking during mastering.

The original single-sided test pressings from 1976/77 were mastered with the DRAW system as were the "educational", non-feature titles at the format's release in December 1978.

The beams from all of the 192 lasers eventually converge onto a single target of deuterium-tritium fuel in hopes to trigger a fusion reaction.

A schematic of a Pockels cell modulating the polarization of light. In this case, the Pockels cell is acting as a quarter wave plate, where linearly-polarized light is converted to circularly-polarized light. With the addition of a Brewster window (left), this change in polarization can be converted to a change in the intensity of the beam, by transmitting only the p-polarized vector component.