Iodine (I2) Reference Cell.
These flame-sealed cells contain a small amount of solid, >98% pure iodine (I2) under vacuum. The concentration of iodine in the vapor phase may be controlled by heating the cell or cooling the tipoff stem. Operating temperatures typically range from 20-70°C. Iodine reference cells are used for calibration of tunable lasers and wavelength meters in the range of 11000-20000 cm-1 (500-910 nm). They may also be used to stabilize laser frequencies via locking to a single absorption line.
The quartz cell body is cylindrical in shape; outer diameter 20 mm; length 100 mm. The tipoff stem is centered on the cell, protruding not more than 10 mm from the cell body. Windows are angled 11° off of normal and have a 2° interior wedge to prevent back-reflection and etalon effects.
