Glan Thompson Polarizers
Glan Thompson polarizer is made of two calcite prisms
or a-BBO prisms cemented together. Two types of Glan Thompsons are
available. One is the standard form and the other is the long form.
Their length to aperture ratios are 2.5 : 1 and 3.0 : 1 respectively.
Glan Thompsons tend to have higher extinction ratio than air spaced
polarizers. In the ultra violet spectrum, their transmission is
limited by absorption in birefriengent materials as well as the
cement layer. a-BBO polarizers and Calcite polarizers can be used
from about 220 to 900nm and 350 to 2300 nm respectively.
The polarizers have the widest field 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 a field angle >26° . The polarized field F1 and F2 of all
these is shown in the plot below.
Angular Field vs Wavelength
Calcite:L/A=2.5 (350-2300nm) |
Calcite:L/A=3.0 (350-2300nm) |
a -BBO, 200-1100nm |
| Specifications |
| Material |
a-BBO, Calcite |
| Wavelength Range |
a-BBO: 200-1100 nm, Calcite: 350-2300 nm |
| Extinction Ratio |
Calcite:<5x10-5 ; a-BBO:<5x10-6
|
| Parallelism |
<1 arc Min |
| Surface Quality |
20-10 |
| Beam Deviation |
< 3 arc minutes |
| Wavefornt Distortion |
λ /4@633nm |
| Damage Threshold |
>200 MW/cm2 |
| Coating |
Single MgF2 |
| Mount |
Black Anodized Aluminium |
Standard Products
1. a -BBO Glan Thompson Polarizer(Special for
DUV, Visible and NIR(200-1100nm)
| Part No. |
L/CA |
Extinction Ratio |
Angular Field(°) |
C.A. f a (mm) |
O.D. f d (mm) |
L±0.1(mm) |
Unit price |
| PGM6006 |
1.6 |
<5x10-6 |
>15 |
6.0 |
15.0 |
18.0 |
$398 |
| PGM6008 |
8.0 |
25.4 |
21.0 |
$438 |
| PGM6010 |
10.0 |
25.4 |
24.5 |
$538 |
| PGM6012 |
12.7 |
25.4 |
28.5 |
$648 |
| PGM6015 |
15.0 |
30.0 |
32.5 |
$758 |
| PGM6020 |
20.0 |
38.0 |
40.7 |
$998 |
2. Calcite Glan Thompson Polarizer (350-2300nm)
| Part No. |
L/CA |
Extinction Ratio |
Angular Field(°) |
C.A. f a (mm) |
O.D. f d (mm) |
L±0.1(mm) |
Unit price |
| PGM7106 |
2.5 |
<5x10-6 |
14-16 |
6.0 |
15.0 |
23.0 |
$238 |
| PGM7108 |
8.0 |
25.4 |
28.0 |
$268 |
| PGM7110 |
10.0 |
25.4 |
33.0 |
$318 |
| PGM7115 |
15.0 |
30.0 |
45.5 |
$428 |
| PGM7206 |
3.0 |
<5x10-6 |
25-28 |
6.0 |
15.0 |
36.0 |
$308 |
| PGM7208 |
8.0 |
25.4 |
32.0 |
$338 |
| PGM7210 |
10.0 |
25.4 |
38.0 |
$428 |
| PGM7212 |
12.7 |
25.4 |
46 |
$498 |
| PGM7215 |
15.0 |
30.0 |
53.0 |
$578 |
