Jun 5 2013
Chromium doped chrysoberyl lasers are called alexandrite lasers. The synthetic alexandrite crystal is grown from the chrysoberyl mineral by the floating zone method. The alexandrite crystal displays its color based on the surrounding lighting. The alexandrite laser was invented in the year 1964.
Chrysoberyl crystal is an aluminate of beryllium, having formula BeAl2O4. The alexandrite is a tunable laser, with the tunable wavelengths varying from 700 to 820 nm. Some of the notable characteristics of this laser are high thermal coefficient, Q-switching, mechanically strong, chemical stability and ability to lase in CW mode. It is best suited for high power laser applications.
The physical properties and applications of this laser are discussed in the sections below.
Laser Properties
| Laser Properties |
| Laser type |
Solid |
| Pump source |
Laser Diode, flash light, mercury arc (for CW mode) |
| Operating wavelength |
700-820 nm |
Physical and Chemical Properties
| Physical and Chemical Properties |
| Chemical formula |
Cr3+:BeAl2O4 |
| Crystal structure |
Orthorhombic |
| Melting point |
1870°C |
| Hardness |
8.5 mohs |
| Thermal conductivity |
0.23 W/cmK |
| Young's modulus |
469 GPa |
Applications
The alexandrite laser is primarily used for cosmetic surgery, mainly for laser hair removal procedures. It is also used for specific medical procedures such as laser lithotripsy.
Some of the other applications of the alexandrite laser are listed below:
- Laser machining – drilling, etching, metal marking
- Industrial – metal coatings, ceramics
- Spectroscopy
- LIDAR
Sources and Further Reading