Silicon Windows


  • Offered Uncoated or with AR Coating for 2 - 5 µm
  • Ø1/2" and Ø1" Sizes Available

WG81050-E1

(Ø1")

WG81050

(Ø1")

WG80530-E1

(Ø1/2")

WG80530

(Ø1/2")

Related Items


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Flat Window Selection Guide
Wavelength Range Substrate Material
180 nm - 8.0 μm Calcium Fluoride (CaF2)
185 nm - 2.1 μm UV Fused Silica
200 nm - 5.0 μm Sapphire
200 nm - 6.0 μm Magnesium Fluoride (MgF2)
220 nm to >50 µm CVD Diamond Windows
230 nm - 1.1 µm UV Fused Silica, Textured Antireflective Surface
250 nm - 1.6 µm UV Fused Silica, for 45° AOI
250 nm - 26 µm Potassium Bromide (KBr)
300 nm - 3 µm Infrasil®
350 nm - 2.0 μm N-BK7
600 nm - 16 µm Zinc Selenide (ZnSe)
1 - 1.7 µm Infrasil®, Textured Antireflective Surface
1.2 - 8.0 μm Silicon (Si)
1.9 - 16 μm Germanium (Ge)
2 - 5 μm Barium Fluoride (BaF2)
V-Coated Laser Windows

Features

  • 1/2" and 1" Diameters Available
  • Ideal for IR Applications in the 1.2 - 8.0 µm Spectral Range
  • Available Uncoated or AR Coated for <1.25% Average Reflectance from 2 - 5 µm

Thorlabs' Precision Monocrystalline Silicon (Si) Windows are offered in Ø1/2" and Ø1" sizes. They are available uncoated or with an AR coating on both sides that provides <1.25% average reflectance from 2 - 5 µm (see the Graphs tab for more details). Silicon offers high thermal conductivity and low density, making it suitable for laser windows. However, since silicon has a strong absorption band at 9 µm, it is not suitable for use with CO2 laser transmission applications.

Thorlabs also offers precision windows fabricated from several other substrates for use in a large variety of laser and industrial applications. For our complete selection, see the Flat Window Selection Guide table to the right. We also offer wedged silicon windows, laser windows with AR coatings centered around commonly used laser wavelengths, and Brewster windows designed to eliminate P-polarized reflected light.

Optic Cleaning Tutorial Optical Coatings Guide
Si Window Transmission
Click to Enlarge

Click for Raw Data
This graph shows the measured transmission of an uncoated silicon window at normal incidence.
AR-Coated Silicon Transmission
Click to Enlarge

Click for Raw Data
This plot gives the measured total transmission of a 5 mm thick, AR-coated silicon window at normal incidence. The blue shaded region denotes the AR coating range, over which Tavg > 94%. Performance outside the specified range is not guaranteed and varies from lot to lot.
Ge Window Transmission
Click to Enlarge

Click for Raw Data
This plot gives the measured reflectance (per surface) at normal incidence of our 5 mm thick, AR-coated silicon window. The average reflectance is <1.25% per surface within the shaded wavelength range of 2 µm - 5 µm.

Posted Comments:
user  (posted 2024-11-01 02:47:23.037)
The 'E coated' silicon windows (WG81050-E) come with a hazardous materials warning on the box (uncoated Silicon windows have no warning on the box). Are you able to say what the hazardous aspect of the E coating is?
blarowe  (posted 2024-11-07 09:35:04.0)
Thank you for contacting Thorlabs. I'm very sorry for the confusion here. It will actually be the silicon itself leading to that warning, and the uncoated windows should have similar warnings.
blarowe  (posted 2024-11-07 09:35:04.0)
Thank you for contacting Thorlabs. I'm very sorry for the confusion here. It will actually be the silicon itself leading to that warning, and the uncoated windows should have similar warnings.
Iga Kamińska  (posted 2023-11-10 11:08:47.737)
Could you please, send me information about the microroughness value? Is the Si window poished both sides?
jpolaris  (posted 2023-11-21 03:54:22.0)
Thank you for contacting Thorlabs. Yes, these Silicon windows are polished on both sides. Unfortunately, we have not characterized the microroughness of these Silicon windows at this time.
Felix  (posted 2023-10-16 11:01:03.933)
Hello, is the Silicon-Window a single-crystal? Whats the orientation and do you have precise measurements of the mechanical properties (elastic modulus, poisson ratio, density).
jdelia  (posted 2023-10-19 01:33:14.0)
Thank you for contacting Thorlabs. These Silicon Windows are high-resistance, Optical Grade, Czochralski Monocrystals. The OEM for this material uses both 111 and 100 orientations for the windows, however there is no flat side to mark the lattice orientation of the windows. You can find the mechanical properties of Silicon in our optical substrates tutorial here: https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=6973&tabname=silicon.
Morken Michael  (posted 2022-09-13 09:52:38.957)
Is there a reflection spectrum available for the uncoated Silicon?
cdolbashian  (posted 2022-09-26 04:43:24.0)
Thank you for reaching out to us Morken. While we do not have experimental data for the cumulative reflections for the uncoated Si windows, I think it is very feasible to use Fresnel reflection coefficient in conjunction with the Sellmeier equation in order to make a fair estimate of the reflection as a function of wavelength. I have contacted you directly with some suggestions regarding the execution of this calculation.
bill sweatt  (posted 2022-02-03 15:31:58.833)
What is the maximum temperature for good transmission for your silicon windows?
cdolbashian  (posted 2022-02-09 05:06:49.0)
Thank you for reaching out to us at Thorlabs! At room temperature we would expect ~50% transmission. Based on some findings in literature, it seems like the transmission is nominally unaffected until temperatures exceeding 300C, and even at 300C the transmission only seems to drop to about 47%. I don't think we would recommend using them in excess of 300C as a general recommendation.
Benjamin Judkewitz  (posted 2019-05-07 15:52:01.43)
Do these exist with AR coarting at 1700 nm?
nbayconich  (posted 2019-05-13 01:00:36.0)
Thank you for contacting Thorlabs. We can provide custom coating options upon request, I will reach out to you directly to discuss our custom capabilities.
feng  (posted 2018-03-07 13:23:46.233)
Hello, do you have a coating from 1.8 um to 3um? just like the silicon wedge provided by your company.
llamb  (posted 2018-03-30 01:53:32.0)
Hello, thank you for contacting Thorlabs. We do not have a standard silicon flat window with that anti-reflection coating, however we may be able to offer a custom product. If you are looking for the flat silicon window but with the 2- 5 um AR coating as on our silicon wedged windows, this particular coating run is not offered frequently so there would be a long lead time. I will reach out to you directly to discuss quoting.
eugen.wiens  (posted 2015-04-27 12:42:14.043)
Hello, what crystal growth process was used for this substrates, what purity does the material have, and how is the crystal oriented in respect to the window's optical axis?
jlow  (posted 2015-05-13 11:25:05.0)
Response from Jeremy at Thorlabs: The silicon windows we sell are only qualified by the optical properties we specified. The growth process, exact purity, and crystal orientation are not controlled explicitly.
a.wienke  (posted 2014-04-29 11:23:19.87)
Hi, Do you also have any transmission data below 2.0 µm? Down to 1.9 µm would be fine for me.
jlow  (posted 2014-04-29 05:08:28.0)
Response from Jeremy at Thorlabs: I will send you this information directly.
elharel  (posted 2014-02-11 17:32:46.72)
Is this amorphous or crystalline silicon?
jlow  (posted 2014-02-13 09:01:28.0)
Response from Jeremy at Thorlabs: These are monocrystalline Si.
tcohen  (posted 2012-05-09 16:09:00.0)
Update from Tim at Thorlabs: Unfortunately, our standard –C coating is typically used with materials of much lower index and would not yield positive results on a Silicon substrate. I have contacted you to continue this discussion.
tcohen  (posted 2012-05-09 14:12:00.0)
Response from Tim at Thorlabs: Thank you for your feedback! We do have 1550 nm AR coated windows utilizing different substrates. For this substrate, we may be able to offer a special with our standard –C coating. I will contact you to get more information on your application and to continue this conversation.
goetz  (posted 2012-05-08 11:24:40.0)
This product would be useful to me if it were AR coated for 1550 nm.
Window Selection Guide (Table Sorted by Wavelength)
Substrate and Window Type Wavelength Range Available AR Coatings Reflectance over AR Coating Rangea Transmission Data Reflectance Data
Calcium Fluoride (CaF2):
Flat or Wedged
180 nm - 8.0 μm Uncoated -
Raw Data
-
-D Coating, 1.65 - 3.0 µm Ravg < 1.0%; Rabs < 2.0% at 0° AOI
Raw Data

Raw Data
UV Fused Silica:
Flat, Wedged, V-Coated Flat,
or V-Coated Wedged
185 nm - 2.1 μm Uncoated
(Flat or Wedged)
-
Raw Data
-
-UV Coating,
245 - 400 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
-C3 Coating,
261 - 266 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-C6 Coating,
350 - 450 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-A Coating,
350 - 700 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
-B Coating,
650 - 1050 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
-C Coating,
1050 - 1700 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
Sapphire:
Flat or Wedged
200 nm - 5.0 μm Uncoated -
Raw Data
-
-D Coating, 1.65 - 3.0 µm Ravg < 1.0% at 0° AOI
Raw Data

Raw Data
-E1 Coating, 2.0 - 5.0 µm Ravg < 1.50%, Rabs < 3.0%
(per Surface, 2.0 - 5.0 µm);
Ravg < 1.75%
(per Surface, 2.0 - 4.0 µm) at 0° AOI

Raw Data

Raw Data
Magnesium Fluoride (MgF2):
Flat or Wedged
200 nm - 6.0 μm Uncoated -
Raw Data
-
Barium Fluoride (BaF2):
Flat or Wedged
200 nm - 11 µm Uncoated
(Wedged Only)
-
Raw Data
-
-E1 Coating, 2 - 5 µm Ravg < 1.25%; Rabs < 2.5% at 0° AOI
Raw Data
Icon
Raw Data
UV Fused Silica, for 45° AOI:
Flat or Wedged
250 nm - 1.6 µm Coating for
250 nm - 450 nm
Ravg < 1.0% at 45° AOI info
Raw Data
Coating for
350 nm - 1100 nm
Ravg < 2.0% at 45° AOI info
Raw Data
Coating for
400 nm - 700 nm
Ravg < 1.0% at 45° AOI info
Raw Data
Coating for
600 nm - 1700 nm
Ravg < 1.5% at 45° AOI info
Raw Data
Coating for
700 nm - 1100 nm
Ravg < 1.0% at 45° AOI info
Raw Data
Coating for
1200 nm - 1600 nm
Ravg < 1.0% at 45° AOI info
Raw Data
Potassium Bromide (KBr):
Flat
250 nm - 26 µm Uncoated - -
Infrasil®:
Flat
300 nm - 3 µm Uncoated -
Raw Data
-
N-BK7:
Flat, Wedged, V-Coated Flat,
or V-Coated Wedged
350 nm - 2.0 μm Uncoated
(Flat or Wedged)
-
Raw Data
-
-A Coating,
350 - 700 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
-C7 Coating,
400 - 700 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-C10 Coating,
523 - 532 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-C11 Coating,
610 - 860 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-B Coating,
650 - 1050 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
-C13 Coating,
700 - 1100 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
C14 Coating,
1047 - 1064 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-C15 Coating,
523 - 532 nm &
1047 - 1064 nm
(V-Coated)
Ravg < 0.5% at 0° AOI - Click to View Index Plot
Raw Data
-C Coating,
1050 - 1700 nm
(Flat or Wedged)
Ravg < 0.5% at 0° AOI -
Raw Data
Zinc Selenide (ZnSe):
Flat or Wedged
600 nm - 16 µm Uncoated -
Raw Data
-
-D Coating, 1.65 - 3.0 µm Ravg < 1.0%; Rabs < 2.0% at 0° AOI
Raw Data

Raw Data
-E4 Coating, 2 - 13 µm
(Only Flat)
Ravg < 3.5%; Rabs < 6% at 0° AOI
Raw Data

Raw Data
-E2 Coating, 4.5 - 7.5 µm
(Only Flat)
Ravg < 1.0%; Rabs < 2.0% at 0° AOI
Raw Data

Raw Data
-E3 Coating, 7 - 12 µm
(Only Wedged)
Ravg < 1.0%; Rabs < 2.0% at 0° AOI
Raw Data
Icon
Raw Data
-G Coating, 7 - 12 µm
(Only Flat)
Ravg < 1% at 0° AOI
Raw Data

Raw Data
Silicon (Si):
Flat or Wedged
1.2 - 8.0 μm Uncoated -
Raw Data
-
-E1 Coating, 2 - 5 µm Ravg < 1.25%; Rabs < 2.5% at 0° AOI
Raw Data
Icon
Raw Data
Germanium (Ge):
Flat or Wedged
1.9 - 16 μm Uncoated, 2.0 - 16 μm -
Raw Data
-
-C9 Coating, 1.9 - 6 µm
(Only Flat)
Ravg < 2% at 0° AOI
Raw Data

Raw Data
-E3 Coating, 7 - 12 µm Ravg < 1.0%; Rabs < 2.0% at 0° AOI
Raw Data
Icon
Raw Data
  • Reflectance is given per surface and each window is coated on both sides.
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Silicon Windows, Uncoated

Item # WG80530 WG81050
Diameter  1/2" (12.7 mm) 1" (25.4 mm)
Diameter Tolerance +0.0 / -0.2 mm
Thickness 3.0 mm 5.0 mm
Thickness Tolerance ±0.1 mm
Clear Aperture >90% Diameter
Parallelism ≤2 arcmin
Surface Flatnessa λ/2 over Clear Aperture
Surface Quality 40-20 Scratch-Dig
Wavelength Range 1.2 - 8.0 μm (Uncoated)
Substrate Siliconb
Transmission Data
Raw Data
  • Measured at 633 nm
  • Click Link for Detailed Specifications on the Substrate
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
WG80530 Support Documentation
WG80530Customer Inspired! Ø1/2" Silicon Broadband Precision Window, Uncoated
$109.29
Lead Time
WG81050 Support Documentation
WG81050Customer Inspired! Ø1" Silicon Broadband Precision Window, Uncoated
$140.17
3 Weeks
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Silicon Windows, AR Coated: 2 - 5 µm

Item # WG80530-E1 WG81050-E1
Diameter  1/2" (12.7 mm) 1" (25.4 mm)
Diameter Tolerance +0.0 / -0.2 mm
Thickness 3.0 mm 5.0 mm
Thickness Tolerance ±0.3 mm
Clear Aperture ≥90% Diameter
Parallelism <3 arcmin
Surface Flatnessa ≤λ/2 over Clear Aperture
Surface Quality 40-20 Scratch-Dig
AR Coating Range 2 - 5 µm (-E1 Coating)
AR Coating Reflectanceb Ravg < 1.25%c; Rabs < 2.5% (0° AOI)
Reflectance Data
Raw Data
Substrate Silicond
Transmission Data
Raw Data
  • Measured at 633 nm
  • Reflectance is given per surface and each window is coated on both sides.
  • Averaged Over Specified AR Coating Range
  • Click Link for Detailed Specifications on the Substrate
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
WG80530-E1 Support Documentation
WG80530-E1NEW!Ø1/2", Silicon Broadband Precision Window, AR Coated: 2 - 5 μm
$158.00
Lead Time
WG81050-E1 Support Documentation
WG81050-E1NEW!Ø1", Silicon Broadband Precision Window, AR Coated: 2 - 5 μm
$188.88
In Stock