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Q-Switches, KD*P Pockels Cells


The EM500 series of KD*P longitudinal Pockels cells have been designed to give the lowest possible switching times using 50Ω line techniques and are normally used for Q-switching lasers.

These cells / q-switches are manufactured from crystals that have been specially selected for their low optical loss and strain free properties. They can be used in the optical range 0.3-1.2μm and are normally supplied with windows optically coated at the customers specified wavelength.

Q-switches can be supplied in either one, two or four terminal configuration and either index matching fluid filled (preferred) or dry with or without anti-reflection coatings on the crystal.

The housing of these Pockels cells / q-switches has been designed to offer good electrical shielding. The metal body which is earthed encloses the crystal with the only opening being the window required to let the light pass through. Electrical safety is also maintained by the use of special high voltage BNC connectors. These also contribute to low radiated emissions. These features make this style of device especially suited to operation in an open environment, such as on optical tables and breadboards.

For a more compact device where shielding and safety are provided by an additional enclosure or housing, see our compact electro-optic Q-switch range


Model No. EM508 EM510 EM512 EM565
Aperture 8mm 10mm 12mm 16mm
Wavelength Range 0.3-1.2μm 0.3-1.2μm 0.3-1.2μm 0.3-1.2μm
Half-wave Voltage @ 1.06μm 6.0kV 6.0kV 6.2kV 6.3kV
Maximum Voltage 10kV 10kV 10kV 10kV
Optical Rise Time < 0.25ns < 0.25ns < 0.25ns < 0.3ns
Contrast Ratio @ 1.06μm > 1000:1 > 1000:1 > 1000:1 > 1000:1
Crystal length 20mm 25mm 25mm 30mm
Capacitance Unterminated 15pf 15pf 15pf 20pf
Damage Threshold
600MW/cm2 600MW/cm2 600MW/cm2 600MW/cm2
Insertion Loss 4% 4% 4% 4%
Terminations H.V.BNC H.V.BNC H.V.BNC H.V.BNC
Finish Black
Physical Dimensions 50mm dia.
50mm long
50mm dia.
55mm long
50mm dia.
55m long
60mm dia.
70mm long
Download Drawing (pdf) Download Interface Drawing Please email

Application Notes for Pockels Cells:

The Linear Electro-Optic Effect
Selecting the Right Pockels Cell
Setting Up the Q-Switch
Pulse Slicing with Pockels Cells
Pulse Picking with 4 Terminal Pockels Cells