Although INRAD Pockels cells can be used for phase modulation, during which sidebands are imprinted onto the frequency of the transmitted light at multiples of the drive frequency of the Pockels cell, these cells are not as efficient as devices that use an optimal crystal orientation and electric field direction and are designed specifically as phase modulators.

Because of the desire for the light beam to experience no birefringence in the absence of an electric field, the light beam propagates along the optic axis of a uniaxial crystal for all standard INRAD Pockels cells.

Crystal Types
Selection of the best crystalline material to use as the Pockels cell medium is determined by the wavelength of operation and the specific performance requirements such as damage threshold, average power handling ability, contrast ratio, extinction ratio, and repetition rate.

KD*P Pockels Cells
KD*P is routinely used for Q-switching applications from the uv out to about 1.1 µm where absorption limits its use in active cavities, although it can be useful at longer wavelengths when a few percent of absorption can be tolerated.

LiNbO₃ Pockels Cells
LiNbO₃ is used at 1.064 µm and longer wavelengths. As a Pockels cell with an electric field applied transverse to the direction of light propagation, it can be configured to operate at a lower voltage than KD*P at 1.064 µm by selecting the thickness and length of the crystal. LiNbO₃ is useful at infrared wavelengths as long as 4.0 µm although the half wave voltage becomes quite high. INRAD offers a damped LiNbO₃ Pockels cell that dramatically decreases piezoelectric ringing and allows the Pockels cell to be used at higher repetition rates.

BBO Pockels Cells
BBO can be useful at wavelengths from the uv out to about 2 µm. The crystal handles high average powers better than either KD*P or LiNbO₃, although it has a relatively small electro-optic coefficient. Hence, for BBO Pockels cells, voltages typically are high. Longer crystals reduce the voltage requirement. Thinner crystals, for which the clear aperture is smaller, also require less voltage for a given application.

Gimbal Mounts for INRAD Pockels Cells
Pockels Cell M/N	Gimbal Mount
PKC21-XX09	815-430 / 1.375
PBC05	815-430 / 1.00
PBC06	815-430 / 1.25
PKC02-XX09, PKC02-XX15, and PKC02-XX20	815-540
PLC01 and PLC01/D	815-540

Ordering Information
Please consult with an INRAD sales engineer before ordering a Pockels cell.
The model number of an INRAD Pockels cell is coded in the following format.
1 2 3 4 5 - 6 7 8 9 / xxxx nm / D

1 -	P for all Pockels cells
2 -	either K for KD*P, L for LiNbO3, or B for BBO
3 -	either C for capacitive or M for impedance matched
45 -	a two digit model number
67 -	either DC for a dry cell, SG for a sol gel coating, FC for a fluid filled cell with FC-43
89 -	a two digit number indicative of the aperture of the cell in mm units
/xxxx -	the wavelength of use
/D -	a designation for a LiNbO3 cell that indicates a piezoelectrically-damped unit

Examples:
Part Number Description

PKC21-SG09/1064nm
KD*P capacitive-type Pockels cell with a 9.5 mm aperture and AR coated for 1064 nm. The crystal faces are AR coated with a sol gel coating for 1064 nm and the windows have a dielectric AR coating at 1064 nm on both sides.

PKC02-FC09/1064nm
KD*P capacitive-type dual crystal Pockels cell with a 9 mm aperture and AR coated for 1064 nm. The cell is fluid filled with an index matching fluid and the windows have a dielectric AR coating at 1064 nm on the outside surfaces.

PLC01-DC08/1318nm/D
LiNbO₃ capacitive-type Pockels cell with a 8 mm aperture and AR coated for 1318 nm. The crystal and windows have a dielectric AR coating at 1318 nm. The unit is piezoelectrically damped.

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