07 Mar 2008
A battery-powered solid-state green laser that emits constant power over a wide temperature range is now commercially available.
Snake Creek Lasers of the US has developed a solid-state green laser that operates over a broad temperature range while maintaining constant laser output. The laser could be deployed in aiming applications for military/law enforcement and for guidance applications in industrial environments.
"For the first time, a battery-driven and temperature-stabilized green diode-pumped solid-state (DPSS) laser is available," Sten Tornegard, marketing manager at Snake Creek Lasers, told optics.org. "No green semiconductor laser currently exists, we have developed a frequency-doubled DPSS laser to fill in the wavelength gap between blue and red diode lasers."
The MiniGreen ETR Series provides 100 mW of continuous-wave output power at 532 nm over a 40 °C temperature operating range with less than 2 W power consumption. Further power settings of 100 mW over 30 K, 100 mW over 40 K or 50 mW over 50 K are also available.
The performance of a DPSS laser (output power, mode quality and power stability for example) are inherently sensitive to changes in ambient temperature. In particular, the output wavelength of the pump diode laser varies by around 0.3 nm per degree C. "Power-hungry thermo-electric coolers (TEC) or ovens are required for reliable emission making DPSS lasers unsuitable for portable or battery-powered applications," commented Tornegard. "Snake Creek has developed a green DPSS laser with +/- 10% power stability over a 50 °C range without TEC requirement, opening the laser up for demanding military and industrial applications."
According to Tornegard there is a strong incentive for switching to green lasers for laser pointer applications to guide human eyes in dynamic processes. Currently red lasers based on III-V semiconductor materials are commonly used for patient positioning, military aiming, and other laser pointer applications. "However, due to concerns for retinal damage, the maximum laser output power for TEM00 beams is limited to 5 or 1 mW in the visible wavelength region," he commented. "By substituting the red (640 nm) laser with an equal power green (532 nm) laser, visual sensitivity is improved by a factor of five in daylight and a factor more than 500 for a dark-adapted eye."
Although Snake Creek Lasers did not disclose details of its DPSS lasers, the company says that it will release more information later this month in the upcoming Defense & Security Conference in Orlando in the US. The company also plans to develop blue DPSS lasers based on its ETR technology.