Compact Pockels Cells for Laser Q-switching
The EM500 range of longitudinal field Pockels cells have been designed to offer the best possible performance in a package which as far as possible encloses the active region of the optical crystal in an earthed metallic casing. This provides good electrical shielding for reduced radiated emissions, and increases user safety. A further safety feature is the use of special high voltage rated HV BNC electrical connectors which have extended shields on the mating plugs which reduce the potential risks of electrical shock should the user handle the live cables when not connected to the Pockels cell. Although this arrangement provides many advantages to the user of these Pockels cells in an open environment (such as on an optical table in a research laboratory) it does increase the physical size of the Pockels cell.
For the manufacturer of Q-switched laser systems, the volume and mass of the optical components is often a major consideration, whilst issues such as radiated emissions and user safety are handled by the equipment enclosure into which the laser system is built. Size and weight therefore can take a higher priority for this user. We therefore produce a range of compact Pockels cells which lack the more bulky machined aluminium alloy housings of the EM500 series and use simpler pin or M4 stud contacts for the electrical connection. This connection reduces the load capacitance of the cell by eliminating the capacitance of the HV BNC connector which is in parallel with the active element.
These devices are housed in an industry standard 35mm diameter design which is allows this Q-switch to drop in to many existing laser head designs without modification. The device can be supplied with special end caps and also fitted wave-plates and polarizers if required. We are always happy to discuss any custom requirements for this OEM Q-switch. We are now able to supply this style of device with apertures of either 8, 10 or 12mm in the same sized housing.
Compact Double Pockels Cell
An exciting recent addition to our compact Pockels cell range is the two crystal or double Pockels cell version. This uses two identical crystals, mounted optically in series but electrically in parallel to provide a halving of the required switching voltage when compared to a single crystal unit. The same 35mm diameter is used which makes for easy replacement in a system built for the single crystal unit, but naturally the total length is greater at 59mm. Also, the capacitance is approximately doubled and the insertion loss is slightly greater at around 6%. As with all our Pockels cells, this may be supplied either filled with an inert index matching fluid (preferred) or may be supplied dry with or without anti-reflection coatings on the crystal faces. For dry cells, a small wedge angle may be applied to the crystals to reduce interference effects if required. A choice of pin contact or M4 stud contacts are also available on this unit.