Wavelength References Inc offers gas cells of all types and configurations. Gas cells are used for wavelength calibration in optical instrumentation and in sensing systems. They are also used in research for spectroscopy and laser wavelength locking.
Almost any gas species either as a pure gas or as a gas mixture can be provided.
Fiber coupled gas cells are offered in different path lengths to match the absorption strength of the gas.
Common Specifications
| Fiber type | SMF28 900 micron tight buffer |
| Fiber connector type | FCPC, FCAPC, SCPC, SCAPC |
| Insertion loss | <3dB (<5dB for 80 cm path) |
| Gas pressure | 0.3Torr to 740Torr ±10% ±0.1Torr |
| Gas purity | >99.9% typical |
| Spectral ripple | <0.1dB P-P over any 5nm span |
| Return loss | >40dB typical |
| Tube windows | Glass with 0.5 degree wedge, custom broadband AR coating for wavelength range of interest |
| Tube construction | Hard sealed (low melting temperature glass), tube lifetime >10 years |
- 3 cm path “Mini” cell
This gas cell is our smallest and lowest cost. It is typically filled with acetylene gas which covers the wavelength range from 1510nm to 1540nm.
- 5 cm path “Mini” cell
This gas cell is often filled with hydrogen cyanide for full C-band coverage from 1528nm to 1563nm and in this case provides a peak line strength of about 1.2db. - 16.5 cm path cell
This tube length is used for our standard hydrogen cyanide gas cell which offers a peak absorption depth of 3.2dB from 1528nm to 1562nm.
- 80 cm path “multipass” gas cell
This device has folded optics and passes the beam through the absorption tube for 5 passes over 80 cm. This device is typically used with gases having weaker absorption lines such as carbon monoxide (both carbon 12 and carbon 13 isotopes), water vapor, and other gases.
- 3cm path copper housing with sapphire windows
This device is used with hydrogen fluoride gas which has good strong absorption lines in the 1260nm to 1340nm region and with other very corrosive gases.
Absorption Tubes can be provided in both glass envelopes as well as copper housings. Wavelength range out to >10micron with Zinc Selenide windows. Almost any gas or gas mixture can be provided.
Common Specifications
| Glass Envelope | 3mm OD to 25mm OD, 1cm to 20 cm length |
| Copper Envelope | OFHC 99.95% copper |
| Glass Window | Schott B270 wedged 0.5 degrees |
| Sapphire windows | C-cut or random, wedged to customer specification |
| Zinc Selenide windows/td> | >To customer specification |
| Gas type | Almost any |
| Gas Pressure | >0.1 Torr to 750 Torr ±10% |
| AR coatings | Typically broadband centered at customer specified wavelength but many choices in stock |
| Tube lifetime | >10 years |
- Glass envelope and wedged windows with diameter from 5mm to 25mm and length from 1cm to 20cm. The end windows are typically anti-reflection coated for the wavelength range of interest and may be tilted as well. They may be filled with almost any gas or gas mixture compatible with glass. The window transmission allows good operation from microns to 2.8 microns.
- Copper envelope with wedged sapphire or selenide windows. This can be offered in various paths and clear aperture. This envelope is used for requirements with corrosive gases or far infrared performance.