Envelope Materials

Clear Fused Quartz

Clear Fused Quartz is a relatively low cost material with a wide spectral transmission and high power handling capability.
It has a spectral transmission down to 200nm and is therefore never used when there is a requirement to block the UV output of the lamp to prevent damage to the laser system components.

Clear Fused Quartz is also prone to solarisation - the pale pink discolouration caused by the reaction of UV with certain naturally occurring impurities in the quartz.

Clear fused quartz is most comonly used in cw lamps bacause they require a high average power handling capability but they do not emit high levels of UV radiation.

Cerium Doped Quartz

Cerium Doped Quartz is Clear Fused Quartz which has been doped with Cerium Oxide. This doping causes the material to block all wavelengths below 382nm and therefore cuts off all of the UV output from the lamp - preventing UV damage to the laser system components. Because the UV is blocked, Cerium Doped Quartz is also less prone to Solarisation.

The UV absorption of Cerium Doped Quartz causes it to fluoresce in the visible spectrum. Some of this fluorescence can be absorbed by the laser rod and can cause a slight increase in laser pumping efficiency. Beacause Cerium Doped Quartz absorbs the UV output of the lamps it cannot be operated at such high average power - typically 15% lower than a similar lamp made in Clear Fused Quartz.

Cerium Doped Quartz is also significantly more expensive than Clear Fused Quartz.

Titanium Doped Quartz

Titanium Doped Quartz is Clear Fused Quartz which has been doped with Titanium Oxide.

This doping causes the material to block all wavelengths below 235nm and therefore cuts off some of the UV output from the lamp.

This material still emits some UV wavelengths and consequently does not prevent damage to laser system components to the same extent as Cerium Doped Quartz. Titanium Doped Quartz does not fluoresce and can suffer from Solarisation.

Consequently, Titanium Doped Quartz is rarely used in laser lamp applications and it's use is usually limited to air cooled lamp applications where ozone creation needs to be prevented.

Pyrex

Pyrex has a significantly lower softening point and power handling capability than Quartz and is rarely used for laser or IPL lamps. First Light never use Pyrex in any of our lamps.