Erbium Doped Glass Lasers – Properties and Applications

Erbium is a chemical element belonging to the category of rare earth metals. The trivalent ion of erbium (Er3+) is often used as the dopant for a number of glass and crystal lasers. Erbium is doped onto a glass substrate (made of silica or phosphate) and used for bulk lasers, amplifiers and fiber lasers.

Erbium-doped lasers require significant excitation density of the ions; typically the laser exhibits a high threshold of pump power. This laser is available in rod, plate, chip and optical fiber forms. When silica substrate is doped with erbium the multi-phonon transition is faster. In order to increase the absorption energy of the laser, it is co-doped with chromium or ytterbium. The Er:glass lasers are known as ‘eye safe’ lasers because their emission wavelengths are absorbed by the eye lens and do not reach the retina.

The physical properties and applications of this laser are discussed in the sections below.

Laser type	Solid
Pump source	Laser Diode
Operating wavelength	1.53-1.56 µm
Chemical Formula	Er:Glass
Hardness Knoop	380
Thermal conductivity	0.61 W/mK
Young's modulus	57.6 GPa

Applications

The primary application of the erbium-doped lasers is in medical procedures, where viewing with the eye is necessary. Typical medical application is in dermatology.
Some of the other applications of the erbium doped glass laser are listed below:
Optical fiber communication
Analytical instrumentation
Rangefinders
Optical amplifiers
Telecommunication.