A copper vapor laser makes use of copper vapors as a lasing medium. It emits yellow and green laser light at 578.2 and 510.6nm of the electromagnetic spectrum, respectively. Lasers made using pure metal vapor produced from elemental copper are difficult to produce because of the high temperature required to form a vapor. Hence, compounds like copper chloride, copper iodide, and copper bromide are used, as they form vapors at low temperatures.
The laser head of the copper vapor laser consists of a refractory ceramic tube that contains a low-pressure buffer gas, neon, and copper pellets. With the application of a pulsed electrical discharge between electrodes at the tube ends, the temperature of the laser head increases to about 1450°C, thereby producing copper vapor at low pressure. The excited electrons collide with vaporized copper atoms and excite these atoms to the upper 2P3/2 and 2P1/2 laser levels. The electrons in the 2P3/2 level decay to the lower 2D5/2 laser level to produce green light, and the 2P1/2 decay to 2D3/2 level to produce yellow laser light.
The laser has excellent power stability, good beam quality, and a long operational lifetime. It also has several characteristics that are useful for precision micromachining, and laser cutting applications.
The copper vapor laser already has a wide range of applications. Owing to its excellent beam characteristics, it has recently been applied for high precision micromachining of materials to 1µm. It can also be used in isotope separation systems, and to excite tunable dye lasers.
Some of the other major applications of a copper vapor laser include:
- High-speed photography
- Dermatological applications
- Pump for dye lasers
Sources and Further Reading