Click to Enlarge
Textured Windows Seal Off the Empty Cell and Minimize Glare

Specifications
Item #	GC20T1	GC20T2	GC50T1	GC50T2
Cell Lengtha	20.0 ± 3.0 mm		50.0 ± 3.0 mm
Path Lengthb	18.0 ± 3.0 mm		48.0 ± 3.0 mm
Cell Outer Diameter	12.7 ± 0.2 mm		25.0 ± 0.2 mm
Cell Clear Aperture	>Ø8.0 mm		>Ø20.0 mm
Textured Window Wavelength Range	400 - 1100 nm	1000 - 1700 nm	400 - 1100 nm	1000 - 1700 nm
Pressure	<10-7 Torr to 5 psi at 25 °C
Fill Tube Length	90.0 mm
Fill Tube Outer Diameter	6.4 mm (0.25")
Fill Tube Inner Diameter	4.0 mm (0.16")
Window Angle	0° ± 1.0°
Window Item #	W40510T1	WGN051T2	W41010T1	WGN101T2
Window Flatness	λ
Window Material	UV Fused Silicac	Infrasil® 302	UV Fused Silicac	Infrasil® 302
Cell Substrate	Fused Silica
Reflectanced	Ravg < 0.25% Over Wavelength Range
Reflectance Data (Click for Plot)d	Raw Data	Raw Data	Raw Data	Raw Data
Transmissione	Tabs ≥ 98% Over Wavelength Range
Transmission Data (Click for Plot)e	Raw Data	Raw Data	Raw Data	Raw Data
Diagram (Click to View)

• Length of the Center of the Cell Including the Windows
• Length of the Center of the Cell Excluding the Windows
• Click the link for detailed specifications on the substrate.
• Per Surface
• Transmission Through One Window

Features

• Glass Cells with Textured Antireflective Windows for Spectroscopy Applications:
  • 20 mm Cell Length with Ø1/2" Windows
  • 50 mm Cell Length with Ø1" Windows
• Two Textured Window Options Available:
  • UV Fused Silica for 400 to 1100 nm
  • Infrasil for 1000 to 1700 nm
• Fused Silica Cell Substrate
• Available with One Ø1/4" Fill Tube
• Custom Design and Manufacturing Services Available (Contact Tech Support)
• Compatible with a Variety of our Glass Cell Heaters (See Mounting & Heating Options Below)

Thorlabs' Empty Glass Cells with UV Fused Silica (UVFS) or Infrasil^®† Textured Broadband Antireflective Flat Windows provide high transmission (≥98% through each window) from 400 to 1100 nm or 1000 to 1700 nm, respectively (see the table to the lower right for transmission graphs). The structured surfaces of the windows have <0.25% reflectance per surface over the wavelength range for reduced glare (see the table to the lower right for reflectance graphs). With their secure hermetic sealing on both ends, these glass cells can protect delicate samples from contamination and ensure reliable performance over time. We also offer a variety of other empty cells for various spectroscopic applications as shown in the selection guide below.

Each cell is made from fused silica, a rugged material known to resist chipping and cracking. All glass cells on this page can hold a vacuum below 10^-7 Torr and withstand pressure up to 5 psi. The post-production cleaning process for these cells consists of an ultrasonic cleaning followed by a methanol rinse. The cell is then connected to a vacuum system and leak tested. The cells are not vacuum sealed when shipped; before using the cell in a vacuum setup, we advise users to follow a similar cleaning process for each cell.

Cells are available with one fill tube which is useful when introducing a sample into the cell and sealing it off for measurements. These fill tubes have a 1/4" outer diameter and are compatible with Ø1/4" compression fittings, such as those found on our KF16C025 and KF25C025 KF-Flange Adapters; for more information see the Vacuum Seal tab. As shown in the video to the top right, custom reference cells can be manufactured upon request, including different cell lengths, cell diameters, or fill tube configurations. Please contact Tech Support with inquiries.

These cells are commonly used in absorption spectroscopy; refer to the Application tab for a general overview of use with absorption spectroscopy. We also offer compact and Herriott multipass cells for gas absorption spectroscopy applications, as well as filled and sealed vapor and acetylene reference cells.

Mounting & Heating Options
The glass cells can be mounted in our V-Clamp Mounts, which are available in standard, kinematic, or Ø1.5" post-compatible versions. Please check that the cell diameter is supported by the mount. The VBC2(/M) Post-Mountable Band Clamp can be used to mount the Ø1" glass cells without marring.

Our HT10K and TLK-H Resistive Foil Heaters can attach to the outside of all the glass cells via adhesive backing. Cells with Ø1" windows can be mounted in our GCH25-75 Glass Cell Heater; this requires swapping out the included Ø6 mm cage rods with four ER2 2" long cage rods. We also offer the GCH25R Cap Heater for cells with Ø1" windows. This heater attaches directly to the end of a cell.

Handling Precautions and Cleaning
Thorlabs' Textured Windows could be contaminated or damaged by moisture, fingerprints, aerosols, or contact with any abrasive material; take precautions to avoid direct contact with the windows. Latex gloves or a similar protective covering should be worn to prevent oil from fingers from reaching the structured surface.

If the surface is comtaminated, the windows may be cleaned by:

• Blowing off dust with clean air or nitrogen.
• Rinsing with solvents, such as isopropyl alcohol, followed by clean air or nitrogen blow-drying.
• Immersing in a basic solution (a mix of ammonium hydroxide and hydrogen peroxide) and/or an acid solution (a mix of hydrogen chloride and hydrogen peroxide) followed by clean air or nitrogen blow-drying.

Standard cleaning methods will result in further contamination and thus should be avoided.

†Infrasil is a registered trademark of Heraeus Quarzglas.

Single-Pass Cells Selection Guide
Empty Glass Cells with Borosilicate Windows	Glass Cells with Textured Antireflective Windows	Empty Glass Cells with Angled Windows	Empty Glass Cells with Brewster Windows	Empty Alumina Cells with Sapphire Windows	Threaded Empty Glass Cells	Threaded Empty Stainless Steel Cells	Vapor Reference Cells	Acetylene Reference Cells	Glass Cell Heaters