Holographic Wire Grid Polarizers


  • Linear Polarizers for 2 - 30 µm Spectral Range
  • Extinction Ratios Better Than 150:1
  • BaF2, CaF2, KRS-5, and ZnSe Substrate Options

WP50H-B

(Ø50 mm)

WP25H-Z

(Ø25 mm)

Related Items


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Maximum Transmission
Click to Enlarge

Transmitted intensity through one polarizer for incident light that is polarized parallel to the transmission axis.

Minimum Transmission
Click to Enlarge

Transmitted intensity through one polarizer for incident light that is polarized perpendicular to the transmission axis.
Wire Orientation Drawing

Features

  • Polarize Light from 2 - 30 µm
  • Extinction Ratios from 150:1 to 300:1 (See Specs Tab)
  • Two Size Options: Ø25 mm and Ø50 mm
  • Mounted in Double Protective Ring with Wire Orientation Indicated

Polarizers pass linearly polarized light while blocking the orthogonal polarization from an unpolarized (or randomly polarized) light source. Thorlabs' holographic wire grid polarizers, which operate over the 2 - 30 µm spectral range (333 - 5000 cm-1), are specially designed for this difficult-to-access regime. They consist of an IR-transparent substrate, such as BaF2, CaF2, KRS-5 (thallium bromoiodide), or ZnSe, upon which linearly spaced grooves are fabricated using holographic methods. Metal is then deposited on these grooves to create a wire grid. Because the wire grid absorbs and reflects radiation that is polarized parallel to the grid, the transmitted radiation is perpendicular to the wires. The orientation of the wires is marked by a line (see diagram to the right). Please note that this is different from our other wire grid polarizers.

These holographic wire grid polarizers offer extinction ratios ranging from 150:1 to 300:1 and come premounted in either a Ø25 mm or Ø50 mm double protective ring mount. See the Specs tab for more details. The wires are oriented parallel to the white line engraved on the mount (see the photograph above). We recommend that the polarizers be used in pairs to provide smooth attenuation over the specified wavelength range and control over the output polarization direction. If two polarizers are used in series with their grids parallel, the achievable extinction ratio easily exceeds 20,000:1.

Such polarizers are commonly used to polarize the output of unpolarized molecular lasers or to attenuate radiation from polarized sources. They can also be used to tune the output of a polarizing beamsplitter. Thorlabs also offers nanoparticle-based linear polarizers for the near- and mid-IR.

Note: The surface of a wire grid polarizer, like any diffraction grating, is extremely delicate, particularly for those fabricated from KRS-5. Never touch the surface of the polarizer, and only handle it by the edge. Careful removal of dust by gentle air flow is the only recommended cleaning procedure.

Additionally, extra care should be taken with the handling of our BaF2, KRS-5, and ZnSe polarizers, as these are hazardous materials. Please wear gloves when handling these items and thoroughly wash your hands afterward. Click here to download a pdf of the MSDS for ZnSe or click here to download the one for BaF2.

Thorlabs will accept all ZnSe polarizers back for proper disposal. Please contact Tech Support to make arrangements for this service.

Item # WP25H-B WP25H-C WP25H-K WP25H-Z WP50H-B WP50H-C WP50H-K WP50H-Z
Material BaF2 CaF2 KRS-5 ZnSe BaF2 CaF2 KRS-5 ZnSe
Extinction Ratio (Typical)a >150:1 (3 µm)
300:1 (10 µm)
>150:1 (3 µm)
300:1 (8 µm)
>150:1 (3 µm)
300:1 (15 µm)
>150:1 (3 µm)
300:1 (10 µm)
>150:1 (3 µm)
300:1 (10 µm)
>150:1 (3 µm)
300:1 (8 µm)
>150:1 (3 µm)
300:1 (15 µm)
>150:1 (3 µm)
300:1 (10 µm)
Outer Diameter 25 mm 50 mm
Clear Aperture Ø18.0 mm Ø34.0 mm
Wire Grid Spacing 2700 Grooves/mm (Nominal)
Substrate Thickness 2.0 mm ± 0.5 mm 3.0 mm ± 0.5 mm
Parallelism ≤3 arcmin
Surface Flatness λ/20 @ 10.6 μm λ/10 @ 10.6 μm λ/20 @ 10.6 μm  λ/10 @ 10.6 μm
Ring Thickness 5.0 mm ± 0.2 mm
Ring Diameter Tolerance +0.0/-0.2 mm
  • The extinction ratio (ER) is the ratio of maximum to minimum transmission of a sufficiently linearly polarized input. When the transmission axis and input polarization are parallel, the transmission is at its maximum; rotate the polarizer by 90° for minimum transmission.

Posted Comments:
Raffaele Colombelli  (posted 2024-02-20 09:27:33.537)
dear Madame/Sir we use BaF2 polarizer in the mid-IR We see important Fabry Perot oscillations vs wavelength do you have in catalog Mid-IR polarizers with AR coating? thanks in advance best regards Raffaele Colombelli
cdolbashian  (posted 2024-03-01 03:39:40.0)
Thank you for reaching out to us with this inquiry! I have contacted you directly to discuss alternatives and to ask exactly which IR range you are looking for.
user  (posted 2023-09-20 08:37:33.697)
Good morning. I am interested in transmission data of KRS and BaF2 polarizers, so as to compare the transmission of my setup. Could you please provide this to me?
cdolbashian  (posted 2023-09-25 10:28:45.0)
Thank you for reaching out to us with this request for additional data. I have contacted you directly to share the information which we have regarding this inquiry. For future technical requests, please feel free to email techsupport@thorlabs.com directly for the fastest reply to these types of inquiries.
user  (posted 2023-04-06 09:54:20.45)
Do you require that this part be kept in a low humidity environment to prevent fogging? Outside of the wire grid are there any other coatings to minimize fogging?
cdolbashian  (posted 2023-08-04 11:34:48.0)
Thank you for reaching out to us with this inquiry. These parts are made with non hydrophilic substrates while the wire grid is made of pure aluminum. In normal lab environments, we would not expect fogging to happen.
Do Hyeon Kim  (posted 2022-03-17 11:24:38.42)
I would like to confirm the transmittance of WP50H-B (BaF2) at the wavelength of visible and NIR regions (0.4-2um).
jdelia  (posted 2022-03-18 03:41:30.0)
Thank you for contacting Thorlabs. I have reached out to you directly to share our extended transmission data.
Jon Murray  (posted 2021-07-13 08:11:21.643)
I would like to know if the holographic wire grid polarisors are suitable as beam-splitters. To determine this I need information on the reflectance properties of the device. The spectral range I am interested in is 5 to 30+ microns so the KRS-5 is most applicable. Assuming these are suitable for use as Beamsplitter would you be able to supply custom devices, larger and possibly a substrate with surfaces titled relative to each other to avoid inter-reflection. Kind regards, Jon.
cdolbashian  (posted 2021-08-27 10:58:16.0)
Thank you for contacting us Jon. We would not recommend using this polarizer as a beam splitter as it absorbs a significant portion of the incoming beam, and we do not have data on the angular and wavelength dependent reflection coefficients through the full wavelength range. I have reached out to you directly to discuss your specific application and the potential for a custom. For future custom inquiries, please feel free to reach out to our "Solutions Team" at TechSales@thorlabs.com.
Tsuyoshi Akiyama  (posted 2019-07-19 22:05:11.157)
Could you tell me the damage threshold (CW laser) of this polarizer? I am looking for a polarizer for 9.6 and 4.8 micron with a high damage threshold.
YLohia  (posted 2019-07-22 03:43:56.0)
Hello, thank you for contacting Thorlabs. Unfortunately, we have not formally tested the damage thresholds of these wire grid polarizers yet. I have reached out to you directly to discuss your application.
gorinb  (posted 2018-02-19 17:07:21.47)
Questions on Holographic Grid Polarizer: What is the spectral transmittance between maximum and minimum transmittance for the 2 to 15um choice
nbayconich  (posted 2018-04-12 02:58:05.0)
Thank you for your feedback. We do not have transmission data for these polarizers in between the maximum and minimum transmission of these polarizers. I will contact you directly to provide the raw data of the max and min transmission. You can determine the transmission of any polarizer by using Malus's law with states that the transmission of a linearly polarized source at some angle Θ with respect to the transmission axis of a polarizer is I=Io*(CosΘ)^2.
chunghsinyang  (posted 2016-09-22 11:26:00.647)
Dear sir, What is the damage threshold of the WP25H-C (CaF2 Holographic Wire Grid Polarizer, Ø25 mm, Mounted) Best regards, C.H. Yang
jlow  (posted 2016-09-23 02:44:26.0)
Response from Jeremy at Thorlabs: We have not tested the laser induced damage threshold for these polarizers but we would recommend limiting the incident power intensity to <50 W/cm^2
zachary.flom  (posted 2014-09-13 21:41:33.017)
Will these polarizers (specifically the BaF2 and CaF2 version) pass a decent fraction of light at 650nm? I just want to make sure our pointing lasers will still be visible after passing through two or three of these (assuming the pointing laser is correctly polarized to pass through). Thanks.
yang.han  (posted 2014-07-03 20:14:20.423)
Do you have 0.5inch Dia, BaF2 wiregrid polarizers? What would be the clear aperture? and thickness? Thank you!
jlow  (posted 2014-08-07 08:55:32.0)
Response from Jeremy at Thorlabs: We can quote this. We will contact you directly for a quote. You can also e-mail us at techsupport@thorlabs.com about this.
bdada  (posted 2011-11-08 13:07:00.0)
Response from Buki at Thorlabs: Thank you for using our Feedback Forum. Unfortunately, we do not specify the wire grid polarizers for THz applications and do not have any data about the performance at 1mm. We have contacted you to see if there are other ways we can assist you with your project.
npa  (posted 2011-11-04 12:07:54.0)
I was wondering if you have any information of the performance of the KRS5 polarizer in the THz regime? How do they do at 1mm wavelengths?
bdada  (posted 2011-07-29 14:49:00.0)
Response from Buki at Thorlabs: We have contacted you with a drawing. The wires run parallel with a spacing of 2700 Grooves/mm. Please contact TechSupport@thorlabs.com if you have further questions.
zoltan.karpati  (posted 2011-07-28 02:35:37.0)
Is there a chance to know the exact shape of the cross-section? I need this info for diffraction simulations. Do you happen to have wire grids w/ simple rectangular cross-section?
jjurado  (posted 2011-03-23 15:45:00.0)
Response from Javier at Thorlabs to malcom.a.watson: Thank you very much for contacting us with your request. Although we have not tested the laser induced damage threshold for these polarizers, we would recommend limiting the incident power intensity to 50 W/cm^2. I will contact you directly for further assistance.
malcolm.a.watson  (posted 2011-03-23 08:56:45.0)
Do these polarisers have known laser damage thresholds, please, for both incident polarisation states?
Thorlabs  (posted 2010-09-02 13:41:00.0)
Response from Javier at Thorlabs to england: we currently do not manufacture waveplates in any of these substrates. However, we are very interested in expanding this product line into the Mid-IR. We will explore this topic a bit further and get back to you with more details.
england  (posted 2010-09-01 21:55:59.0)
Do you make a quarter wave plate with KRS-5 or any of the other materials (KF2, ZnF2, ZnSe) in the wavelength range 3 to 5 microns? We want to detect elliptically polarized IR radiation.
Thorlabs  (posted 2010-07-22 10:59:25.0)
Response from Javier at Thorlabs to m.kaucikas: Thank you for your feedback. The wire grid polarizers do not depolarize the reflected beam. Also, we specify a surface flatness of ?/20 @ 10.6 µm for Ø25 mm Polarizers and ?/10 @ 10.6 µm for Ø50 mm Polarizers, so the amount of distortion in the beam is negligible. However, the beam quality is affected slightly by the KRS-5 polarizers.
m.kaucikas  (posted 2010-07-09 16:56:33.0)
I am also interested in reflection from WGP. But I have linearly polarized beam falling onto WGP for reflection. Will it depolarize reflected beam? Will there be any distortions in the beam?
Javier  (posted 2010-06-11 21:11:01.0)
Response from Javier at Thorlabs to last poster: The surface of a wire grid polarizer is extremely delicate. Nothing should ever be allowed to touch the surface of the polarizer. Handling, when necessary, should be by the edge only and with protected fingers. Careful removal of dust by gentle air flow is the only cleaning procedure recommended.
user  (posted 2010-06-11 16:34:29.0)
How do you clean those polarizers?
klee  (posted 2009-12-07 12:13:52.0)
A response from Ken at Thorlabs to tkragh: The index lines on the housing indicate which side the grooves are located, and are parallel to the direction of the grooves. When the plane of polarization of linearly polarized incident light is parallel to the direction of the grooves, the incident light is reflected, and the transmitted light is at a minimum. When the polarization plane is perpendicular to the direction of the grooves, the transmitted light is at a maximum.
tkragh  (posted 2009-12-05 13:04:15.0)
I have a simple question about polarization angle conventions. Does the index line marking on the mounting ring correspond to the orientation of the wire-grid, or the orientation of the outgoing EM-field? In other words, if the index lines on the ring are orientated Up/Down (12oclock/6oclock), will the outgoing EM-field be horizontally polarized? Thanks.
hongwei  (posted 2008-07-10 16:50:24.0)
The "Overview" mentions that the clear aperture of this product is 43mm. But I believe it should be 34mm as mentioned in the AutoCAD drawing.
Tyler  (posted 2008-06-25 14:37:01.0)
A response from Tyler at Thorlabs to hongwei: Although Thorlabs can often provide custom parts, we are unable to produce a 3 inch diameter BaF2 wire grid polarizer. Thank you for bringing your inquiry to us and I am sorry we are not able to produce your part.
hongwei  (posted 2008-06-25 10:04:06.0)
Hi, We are looking for a BaF2 wire grid polarizer with diameter as large as 3 inches. Do you take customer order? Hong Wei
technicalmarketing  (posted 2008-02-14 14:25:09.0)
Due to surface reflections, the reflected beam will contain both polarizations (E-vectors both parallel to and perpendicular to the wire). Therefore, the reflected light doesnt have a pure polarization. However, you could use a second wire grid polarizer in the reflected beam path to choose light polarized in a particular direction.
bret.cannon  (posted 2008-02-14 14:02:08.0)
What is the polarization purity of the light reflected from your wire grid polarizers? Thanks, Bret Cannon

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 TP:TS > 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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Ø25 mm Mounted Wire Grid Polarizers

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
WP25H-B Support Documentation
WP25H-BBaF2 Holographic Wire Grid Polarizer, Ø25 mm, Mounted
$1,519.35
3-5 Days
WP25H-C Support Documentation
WP25H-CCaF2 Holographic Wire Grid Polarizer, Ø25 mm, Mounted
$1,312.65
3-5 Days
WP25H-K Support Documentation
WP25H-KKRS-5 Holographic Wire Grid Polarizer, Ø25 mm, Mounted
$1,981.35
3-5 Days
WP25H-Z Support Documentation
WP25H-ZZnSe Holographic Wire Grid Polarizer, Ø25 mm, Mounted
$1,494.40
3-5 Days
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Ø50 mm Mounted Wire Grid Polarizers

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
WP50H-B Support Documentation
WP50H-BBaF2 Holographic Wire Grid Polarizer, Ø50 mm, Mounted
$1,907.81
3-5 Days
WP50H-C Support Documentation
WP50H-CCaF2 Holographic Wire Grid Polarizer, Ø50 mm, Mounted
$1,773.58
3-5 Days
WP50H-K Support Documentation
WP50H-KKRS-5 Holographic Wire Grid Polarizer, Ø50 mm, Mounted
$3,037.51
3-5 Days
WP50H-Z Support Documentation
WP50H-ZZnSe Holographic Wire Grid Polarizer, Ø50 mm, Mounted
$2,028.96
3-5 Days