Mounted alpha-BBO UV Glan-Thompson Polarizer

Designed for UV Laser Polarization Applications
Polarization Extinction Ratio >100 000:1
Laser Quality α-BBO Crystal Mounted in Ø1" Housing
Single-Layer MgF₂ Antireflection Coating Centered at 400 nm

GTHB10M

α-BBO Glan-Thompson Polarizer Mounted in Ø1" Housing

Application Idea

GTHB10M Polarizer Mounted in an SM1L10 Lens Tube and PRM1 Rotation Mount Assembly for Repeatable Polarization Control

Related Items

Crystal Polarizers

SM-Compatible Rotation Mounts

Ø1" to SM1 Thread Adapter

Polarimetry

Lens Tube Systems

Wave Plates

Polarizing Beamsplitter Cubes

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Overview
Graphs
Alpha-BBO
Mounting
Polarizer Guide
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Item #	GTHB10M
Extinction Ratio^a	>100 000:1
Wavelength Range	230 to 900 nm
Substrate	Laser Quality α-BBO^b (Low Scatter)
Wavefront Distortion	λ/4 at 633 nm
Beam Deviation	<3 arcmin
Surface Quality^c	20-10 Scratch-Dig
Clear Aperture	>10.0 mm x 10.0 mm
Dimensions	Ø1.00" x 0.85" (Ø25.4 mm x 21.7 mm)

For the transmitted beam. The extinction ratio (ER) is the ratio of the maximum transmission of a sufficiently linearly polarized signal when the polarizer’s axis is aligned with the signal to the minimum transmission when the polarizer is rotated by 90°.
Click link for detailed specifications on the substrate.
For Input and Output Faces

Features

High Extinction Ratio: >100 000:1
230 to 900 nm Operation
Single-Layer AR (SLAR) MgF₂ Coating Centered at 400 nm
Clear Aperture >10.0 mm x 10.0 mm
Fabricated from Laser-Quality α-BBO
Glan-Thompson Design (Cemented Birefringent Crystal Prisms)

Thorlabs' Mounted α-BBO Glan-Thompson Polarizer is specifically designed to deal with short-wavelength laser light with transmission in the UV region while maintaining extremely high polarization purity (>100 000:1). The mounts consist of a black aluminum housing. The GTHB10M polarizer has a Ø1" outer diameter and can be conveniently held inside our Ø1" Lens Tubes. This allows the user to easily mount this polarizer to a rotation stage, such as the PRM1 Precision Rotation Mount for Ø1" optics. Please see the Mounting tab for more details.

This polarizer has a single-layer MgF₂ antireflective coating (SLAR), centered at 400 nm. This coating also serves as a protective layer that prevents the hygroscopic α-BBO substrate from interacting with moisture in the environment. Please see the Graphs tab for coating reflectivity data. For alignment, it should be noted that the wide field of view of Glan-Thompson polarizers varies with the wavelength and entrance orientation of incident light; for more information on the field of view please see the Graphs tab.

Click to Enlarge

This Glan-Thompson polarizer consists of two cemented prisms made from the laser-quality α-BBO. Unpolarized light enters the polarizer and is split at the interface between the two crystals. The ordinary rays are reflected at each interface, causing them to be scattered and partially absorbed by the polarizer housing. The extraordinary rays pass straight through the polarizer, providing a polarized output.

Note: As with all Glan-Thompson polarizers, the maximum optical intensity is limited by the cemented prism interface. For higher-power applications, Thorlabs offers a variety of Crystal Polarizers that can handle energy densities up to 20 J/cm².

The typical transmission and reflectivity of an α-BBO Glan-Thompson polarizer is shown in the graphs below. The blue shading indicates the operating wavelength range 230 - 900 nm. The reflectivity plot represents the performance of the coating only, not including internal losses of the polarizer. The transmission plot includes both reflectivity and transmission through the polarizer (including any internal losses).

Click to Enlarge
Click Here for Raw Data
The reflection plot above shows the typical reflectivity of the MgF₂ SLAR Coating on our GTHB10M Glan-Thompson α-BBO Polarizer, not including internal losses. While the specified operating range is 230 - 900 nm, the reflectivity remains low out to 2.0 µm.

Click to Enlarge
Click Here for Raw Data
The transmission plot above shows the typical transmission of a GTHB10M Glan-Thompson α-BBO Polarizer, including any internal losses. While the specified operating range is 230 - 900 nm, the transmission remains above 80% out to 2.0 µm. The transmission is valid for linearly polarized light aligned with the mark on the housing of the polarizer. The performance data shown above may vary from lot to lot and is not guaranteed.

Click to Enlarge
Click Here for Raw Data
The Fields of View (FOV) of the Glan-Thompson Polarizer are shown above. The side that absorbs the ordinary ray has an FOV that decreases as the wavelength increases (FOV 1). The opposite side has an FOV that increases as the wavelength increases (FOV 2).

Glan-Thompson Polarizers feature a field of view (FOV) that varies with both wavelength and entrance orientation. The FOV of the internal prisms must be considered during alignment and collimation procedures. The side that absorbs the ordinary ray has an FOV that decreases as the wavelength increases (FOV 1). The opposite side has an FOV that increases as the wavelength increases (FOV 2). The FOV of Glan-Thompson polarizers is typically greater than the FOV of Glan-Taylor polarizers.

Polarization-Dependent Refraction
Glan-Thompson α-BBO Polarizer

General
Thorlabs' α-BBO polarizers are all based on high-grade, birefringent α-BBO crystals. Due to the birefringent nature of α-BBO, waves polarized in the direction of the optical axis propagate with a different index of refraction than waves polarized orthogonally to the optical axis. In our Glan-Thompson polarizers, this birefringence causes the ordinary polarization component of an incident beam to undergo total internal reflection at an internal crystal-to-epoxy interface. The light transmitted through the polarizer then consists of only the remaining extraordinary polarization component. While these transmitted extraordinary rays are highly polarized, the reflected ordinary rays are only partially polarized.

Our Glan-Thompson, Glan-Laser, and Glan-Taylor polarizers are designed as polarizer elements that remove the reflected ordinary polarization component of a beam. These polarizers are built out of two prisms, as shown in the drawing to the right. They are only designed to work with well collimated light beams; converging and diverging input beams may not exhibit proper polarization and incidence angle at the internal interface. Since α-BBO is a soft crystal that is easily damaged, all of our α-BBO polarizers are offered in metal housings. With convenient threadings and adapters, these housings can easily be mounted into our opto-mechanical products.

Field of View
α-BBO polarizers feature a field of view (FOV) that varies with both wavelength and entrance orientation. The FOV of these prisms must be considered during alignment and collimation procedures. One side of the polarizer has an FOV that decreases with increasing wavelength (FOV 1), while the opposite side has an FOV that increases at longer wavelengths (FOV 2).

Click to Enlarge

Field of View Angle Orientation

Transmission
Thorlabs uses only the highest quality synthetic α-BBO in our polarizing prisms. The transmission curve of the α-BBO polarizer is shown on the Graphs tab. Variations during the manufacturing of the α-BBO crystal can affect the transmission curve.

Figure 2

Figure 1

secure polarizer's position by using spanner wrench

Figure 4

Figure 3

Mounting the GTHB10M

The GTHB10M polarizer can be mounted to a PRM1 rotation mount by using one of our Ø1" Lens Tubes:

Remove the retaining rings that come with the PRM1 rotation mount and the lens tube.
Screw the threaded end of the lens tube into the rotation mount as shown in Figure 1.
Once the lens tube is threaded (Figure 2), insert the mounted polarizer into the other end of the lens tube (see Figure 3)
Secure the polarizer into place using the retaining ring included with the lens tube.
An SPW602 spanner wrench can be used to tighten the retaining ring (Figure 4).

Note: The SM1P1 Ø1" to SM1 adapter can be used in place of the lens tube when space is not available for the extra length of the lens tube.

Polarizer Selection Guide

Thorlabs offers a diverse range of polarizers, including wire grid, film, calcite, alpha-BBO, rutile, and beamsplitting polarizers. Collectively, our line of wire grid polarizers offers coverage from the visible range to the beginning of the Far-IR range. Our nanoparticle linear film polarizers provide extinction ratios as high as 100 000:1. Alternatively, our other film polarizers offer an affordable solution for polarizing light from the visible to the Near-IR. Next, our beamsplitting polarizers allow for use of the reflected beam, as well as the more completely polarized transmitted beam. Finally, our alpha-BBO (UV), calcite (visible to Near-IR), rutile (Near-IR to Mid-IR), and yttrium orthovanadate (YVO₄) (Near-IR to Mid-IR) polarizers each offer an exceptional extinction ratio of 100 000:1 within their respective wavelength ranges.

To explore the available types, wavelength ranges, extinction ratios, transmission, and available sizes for each polarizer category, click More [+] in the appropriate row below.

Wire Grid Polarizers

Film Polarizers

Beamsplitting Polarizers

alpha-BBO Polarizers

Calcite Polarizers

Quartz Polarizers

Magnesium Fluoride Polarizers

Yttrium Orthovanadate (YVO₄) Polarizers

Rutile Polarizers

Click on the graph icons in this column to view a transmission curve for the corresponding polarizer. Each curve represents one substrate sample or coating run and is not guaranteed.
Mounted in a protective box, unthreaded ring, or cylinder.
Available unmounted or in an SM05-threaded (0.535"-40) mount that indicates the polarization axis.
Available unmounted or in an SM1-threaded (1.035"-40) mount that indicates the polarization axis.
PBS519: Average T_P:T_S > 1000:1
Available unmounted or mounted in cubes for cage system compatibility.
Calcite's transmittance of light near 350 nm is typically around 75% (see Transmission column).
Available unmounted or in an unthreaded Ø1/2" housing.
The transmission curves for calcite are valid for linearly polarized light with a polarization axis aligned with the mark on the polarizer's housing.
The 1064 nm V coating corresponds to a -C26 suffix in the item number.
Available unmounted or mounted in a protective box or unthreaded cylinder that indicates the polarization axis.

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Polarizer Type	Wavelength Range	Extinction Ratio	Transmission^a	Available Sizes
Wire Grid Polarizers on Glass Substrates	420 nm - 700 nm	>683:1 (Unmounted) >800:1 (Mounted)		12.5 mm x 12.5 mm, Ø25.0 mm^b, 25.0 mm x 25.0 mm, and 50.0 mm x 50.0 mm
Wire Grid Polarizers on Glass Substrates	250 nm - 4 µm	>10:1 from 250 nm - 4 µm >100:1 from 300 nm - 4 µm >1000:1 from 600 nm - 4 µm >10 000:1 from 2.25 µm - 4 µm		12.5 mm x 12.5 mm, Ø25.0 mm^b, 25.0 mm x 25.0 mm, and 50.0 mm x 50.0 mm
Wire Grid Polarizing Beamsplitter Cubes (Unmounted or 30 mm Cage Cube)	400 nm - 700 nm	>1 000:1 (AOI: 0° - 5°) >100:1 (AOI: 0° - 25°)	P-Pol. S-Pol.	1"^f
Holographic Wire Grid Polarizers	2 µm - 12 µm	150:1 at 3 µm 300:1 at 10 µm		Ø25.0 mm^b and Ø50.0 mm^b
	2 µm - 9 µm	150:1 at 3 µm 300:1 at 8 µm
	2 µm - 30 µm	150:1 at 3 µm 300:1 at 15 µm
	2 µm - 18 µm	150:1 at 3 µm 300:1 at 10 µm
MIR Wire Grid Polarizers on Silicon Substrates	3 µm - 5 µm	>1000:1		12.5 mm x 12.5 mm^b, Ø25.0 mm^b, 25.0 mm x 25.0 mm^b, and 50.0 mm x 50.0 mm^b
MIR Wire Grid Polarizers on Silicon Substrates	7 µm - 15 µm	>10,000:1		12.5 mm x 12.5 mm^b, Ø25.0 mm^b, 25.0 mm x 25.0 mm^b, and 50.0 mm x 50.0 mm^b

Polarizer Type	Wavelength Range	Extinction Ratio	Transmission^a	Available Sizes
Nanoparticle Linear Film Polarizers	365 nm - 395 nm	>1000:1 from 365 nm - 395 nm >10 000:1 from 369 nm - 390 nm >100 000:1 from 372 nm - 388 nm		Ø12.5 mm^c and Ø25.0 mm^d
	480 nm - 550 nm	>10 000:1 from 480 nm - 550 nm		Ø12.5 mm^c and Ø25.0 mm^d
	510 nm - 800 nm	>1000:1 from 510 nm - 800 nm >10 000:1 from 520 - 740 nm >100 000:1 from 530 - 640 nm		Ø12.5 mm^c and Ø25.0 mm^d
	550 nm - 1500 nm	>10 000:1 from 550 nm - 1500 nm >100 000:1 from 600 nm - 1200 nm		Ø12.5 mm^c and Ø25.0 mm^d
	650 nm - 1100 nm	>200:1 from 650 nm - 695 nm >1000:1 from 695 nm - 1100 nm		Ø1/2"^c and Ø1"^d
	650 nm - 2000 nm	>1000:1 from 650 nm - 2000 nm >10 000:1 from 750 nm - 1800 nm >100 000:1 from 850 nm - 1600 nm		Ø12.5 mm^c and Ø25.0 mm^d
	1 µm - 3 µm	>1000:1 from 1 µm - 3 µm >10,000:1 from 1.2 µm - 3 µm		Ø12.5 mm^c and Ø25.0 mm^d
	1.1 µm - 1.8 µm	>1000:1 from 1.1 µm - 1.8 µm		Ø1/2"^c and Ø1"^d
	1.26 µm - 1.36 µm	>10 000:1 from 1.26 µm - 1.36 µm		Ø12.5 mm^c and Ø25.0 mm^d
	1.50 µm - 1.60 µm	>10 000:1 from 1.50 µm - 1.60 µm		Ø12.5 mm^c and Ø25.0 mm^d
	1.5 µm - 5 µm	>1000:1 from 1.5 µm - 5 µm >10 000:1 from 2 µm - 4.5 µm		Ø12.5 mm^c and Ø25.0 mm^d
Economy Film Polarizers	400 nm - 700 nm	>100:1 from 400 nm - 500 nm >1000:1 from 500 nm - 700 nm >5000:1 from 530 nm - 690 nm		2" x 2"
Economy Film Polarizers	600 nm - 1100 nm	>400:1 from 600 nm - 1100 nm >1000:1 from 600 nm - 940 nm		2" x 2"
Economy Laminated Film Polarizers	400 nm - 700 nm	>100:1 from 400 nm - 500 nm >1000:1 from 500 nm - 700 nm >5000:1 from 530 nm - 690 nm		Ø1/2", Ø1", and Ø2"
	600 nm - 1100 nm	>1000:1 from 600 nm - 950 nm >400:1 from 600 nm - 1100 nm		Ø1/2", Ø1", and Ø2"
	1050 nm - 1700 nm	>1000:1 from 1050 - 1400 nm >2000:1 from 1400 - 1700 nm		Ø1/2", Ø1", and Ø2"

Polarizer Type	Wavelength Range	Extinction Ratio	Transmission^a	Available Sizes
Polarizing Plate Beamsplitters	405 nm	>10 000:1		Ø1" and 25 mm x 36 mm
	532 nm
	633 nm
	780 nm
	808 nm
	1030 nm
	1064 nm
	1310 nm
	1550 nm
Broadband Polarizing Beamsplitter Cubes (Unmounted, 16 mm Cage Cube, or 30 mm Cage Cube)	420 nm - 680 nm	1000:1^e		5 mm, 10 mm, 1/2", 20 mm^f, 1"^f, and 2"
	620 nm - 1000 nm
	700 nm - 1300 nm
	900 nm - 1300 nm
	1200 nm - 1600 nm
Wire Grid Polarizing Beamsplitter Cubes (Unmounted or 30 mm Cage Cube)	400 nm - 700 nm	>1 000:1 (AOI: 0° - 5°) >100:1 (AOI: 0° - 25°)	P-Pol. S-Pol.	1"^f
Laser-Line Polarizing Beamsplitter Cubes (Unmounted or 30 mm Cage Cube)	532 nm	3000:1		10 mm, 1/2", 1"^f
	633 nm
	780 nm
	980 nm			1"^f
	1064 nm			10 mm, 1/2", 1"^f
	1550 nm			10 mm, 1/2", 1"^f
High-Power Laser-Line Polarizing Beamsplitter Cubes (Unmounted or 30 mm Cage Cube)	355 nm	2000:1		1/2" and 1"^f
	405 nm
	532 nm
	633 nm
	780 - 808 nm
	1064 nm
High-Power, Broadband, High Extinction Ratio Polarizers	700 nm - 1100 nm	> 1000:1 (700 - 1100 nm) > 5000:1 (750 - 1000 nm) > 10 000:1 (800 - 900 nm)		12.7 mm (Input/Output Face, Square)
High-Power, Broadband, High Extinction Ratio Polarizers	900 nm - 1300 nm	>1000:1 (900 - 1300 nm) >10 000:1 (900 - 1250 nm) >100 000:1 (980 - 1080 nm)		10 mm and 5 mm (Input/Output Face, Square)
Calcite Beam Displacers	350 nm^g - 2.3 µm (Uncoated)	-		10 mm^b (Clear Aperture, Square)
Yttrium Orthovanadate (YVO₄) Beam Displacers	488 nm - 3.4 µm (Uncoated)	-		>3 mm x 5 mm Ellipse^h (Clear Aperture)
Yttrium Orthovanadate (YVO₄) Beam Displacers	2000 nm (V Coated)	-		>3 mm x 5 mm Ellipse^h (Clear Aperture)

Polarizer Type	Wavelength Range	Extinction Ratio	Transmission^a	Available Sizes
alpha-BBO Glan-Laser Polarizers	210 nm - 450 nm	100 000:1		5 mm^b and 10 mm^b (Clear Aperture, Square)
	220 nm - 370 nm
	405 nm
Wollaston Prism Polarizers	190 nm - 3500 nm			Ø10 mm^b (Clear Aperture)

Polarizer Type	Wavelength Range	Extinction Ratio	Transmission^a,h	Available Sizes
Glan-Laser Calcite Polarizers	350 nm^g - 2.3 µm (Uncoated)	100 000:1		5 mm^b, 10 mm^j, and 15 mm^b (Clear Aperture, Square)
	350 nm^g - 700 nm (A Coated)
	650 nm - 1050 nm (B Coated)
	1050 nm - 1700 nm (C Coated)
	1064 nm (V Coated)^j
Glan-Taylor Calcite Polarizers	350 nm^g - 2.3 µm (Uncoated)			5 mm^b, 10 mm^b, and 15 mm^b (Clear Aperture, Square)
	350 nm^g - 700 nm (A Coated)
	650 nm - 1050 nm (B Coated)
	1050 nm - 1700 nm (C Coated)
Glan-Thompson Calcite Polarizers (Unmounted or Mounted)	350 nm^g - 2.3 µm (Uncoated)			5 mm^k and 10 mm^k (Clear Aperture, Square)
	350 nm^g - 700 nm (A Coated)
	650 nm - 1050 nm (B Coated)
Double Glan-Taylor Calcite Polarizers	350 nm^g - 2.3 µm (Uncoated)			9 mm^b (Clear Aperture, Square)
Beam Displacers	350 nm^g - 2.3 µm (Uncoated)			10 mm^b (Clear Aperture, Square)
Wollaston Prism Polarizers	350 nm^g - 2.3 µm (Uncoated)			Ø10 mm^k (Clear Aperture)
	350 nm^g - 700 nm (A Coated)
	650 nm - 1050 nm (B Coated)