Opto Sigma

• High power capacity: up to 500MW/cm2 pulsed
• Made from high optical quality natural calcite
• Conveniently mounted in a metal cell
• Available with two, one or no escape ports for extra power capacity
• Excellent extinction ratio of 5x10-5

Glan laser prisms are a form of calcite prism which has been adapted for high power laser use. The two prism sections are polished at an angle between the critical angles of the e and o rays for the incoming light and are air-spaced and mounted within absorbing black glass in a cell. As light enters the polarizer one polarization orientation of the beam is refracted at a different angle from the other. Thus the e-ray hits the air-spaced interface at an angle below Brewster’s angle and is transmitted. The o-ray is totally reflected out of the prism into either the black glass or the escape port. Normally they are supplied in a cylindrical cell but the cell can be cut away on one or both sides to provide an exit path for the unwanted beam. The escape port type has a greater power handling capacity than the plain metal mounts because the unwanted energy can be dumped outside the cell rather than being absorbed within it. The advantage of 2 ports is that light can enter the prism from either direction.