WASHINGTON, DC - A research team in China has demonstrated a new way to produce continuous streams of laser light in a desirable portion of the infrared spectrum. Their achievement provides another potentially useful source of infrared laser light, which is used in medicine, video displays, materials processing, and spectroscopy. The results are reported in the July issue of Optics Express.
Rui Zhou and co-workers at Tianjin University in China constructed their new infrared laser out of a purple crystal called Nd:YVO 4 (neodymium-doped yttrium orthovanadate). Compared to Nd:YAG, the Nd:YVO 4 material is slightly cheaper and its ability to absorb energy efficiently may be particularly suitable for making practical versions of miniature lasers on a chip. In addition, the 1386-nm wavelength of the infrared light may provide slightly better performance in certain applications, such as laser machining, that currently use slightly shorter wavelengths of infrared light.
The researchers energize the crystal by using a separate diode laser for pumping. In a technique called “diode-end-pumping,” the diode laser’s light travels in the same direction as the infrared laser beam it produces. Compared to the “side-pumping” method, in which the pump laser travels perpendicular to the outgoing laser beam, diode-end pumping has several advantages, such as higher efficiency, good beam quality, and a smaller volume for the laser system.
With their design, the researchers achieved a maximum output power of 305 milliwatts (mW), with an input power of 4.24 W. The researchers strive to increase the efficiency of this laser and power by improving the output coupler. While no unique applications for this specific laser design are envisioned, the researchers believe that the combination of Nd:YVO 4 ‘s desirable properties and the usefulness of the 1386-nm wavelength may inspire novel applications, particularly in medicine, fiberoptics, and laser machining.
For more information, see “Continuous-wave operation at 1386 nm in a diode-end-pumped Nd:YVO 4 laser,” by Rui Zhou, Baigang Zhang, Xin Ding, Zhiqiang Cai, Wuqi Wen, Peng Wang, Jianquan Yao, College of Precision Instrument and Optoelectronics Engineering, Institute of Laser and Optoelectronics, Tianjin University.