Vapor Wavelength Reference Cells

PGB Optical offers high quality vapor wavelength reference cells and gas cells for spectroscopy.

We carry the following vapor wavelength reference cells: Rubidium (Rb) cells, Cesium (Cs) cells, Iodine (I) cells, Sodium (Na) cells, Potassium (K) cells, Thallium (Tl) cells, or Indium (In) cells. We also offer isotopically enriched Rubidium cells (85 and 87) and Potassium cells (41)*. The purity level of the natural elements used in manufacturing all vapor cells is greater than 99% and is then distilled to an even higher purity during the filling process. Upon request, we offer buffer gases like Helium, Neon, Argon, Krypton, Xenon, Nitrogen, and Ethane as well as paraffin coating and OTS coating.

 *Due to the very high cost of Potassium 40 material, PGB Optical no longer offers reference cells filled with K40 vapor. 

All vapor cells are helium leak checked and then baked under vacuum to the 10-8 Torr range before they are filled with the selected element.

PGB Optical also offers gas cells filled with Acetylene, Hydrogen Cyanide (Isotope 12 and 13), Carbon Monoxide (Isotope 12 and 13), and Methane. All gases used in manufacturing process have a purity level greater than 99%.

Reference cells are available in the following materials and configurations:

Borosilicate with flat windows attached parallel or angled

Quartz with flat, high-quality fused silica windows attached parallel or angled

Quartz with wedged, high-quality fused silica windows attached parallel or angled

Quartz with flat, anti-reflective (AR) coated high-quality fused silica windows attached parallel or angled


Alkali Vapor Wavelength Reference Cells – Stock Part Numbers

(Click on the links below for additional information and pricing)

Rubidium Cells

Cesium Cells

Potassium Cells

Sodium Cells

Borosilicate Cells

25 mm OD x 75 mm Path Length






19 mm OD x 75 mm Path Length with 2 Degree Wedged Windows Attached at 11 Degree Angle