Glan Thompson Polarizers

The Glan Thompson polarizer is made of two calcite prisms or α-BBO prisms cemented together. Two types of Glan Thompsons are available: the standard form and the long form with length to aperture ratios of 2.5 : 1 and 3.0 : 1 respectively. Glan Thompsons tend to have a higher extinction ratio than air spaced polarizers. In the ultra violet spectrum, their transmission is limited by absorption in the birefriengent materials as well as the cement layer. Calcite and α-BBO polarizers can be used from about 350 to 2300 nm and 200 to 1100nm respectively.

These polarizers have the widest acceptance angle of any design. The standard form of this polarizer with 2.5:1 length to aperture ratio has a full acceptance cone angle of more than 15° @ 589nm, symmetric about the input axis, whilst the long form with 3:1 ratio has an acceptance angle >26° .

As with all of our optics, we will gladly provide these items custom designed to your particular requirements.

As an alternative, we offer a selection of standard items as specified below.