Component manufacturer and distributor The Optoelectronics Company Ltd of Henham, UK has launched a range of direct-emission 520nm green laser diode modules that are said to offer OEMs and system integrators a realistic, cost- and energy-efficient alternative to low-tech DPSS (diode-pumped solid-state) green laser modules.
Green DPSS laser modules are generally large, expensive and noisy, with low thermal stability. Green light is produced by the cumbersome method of doubling the frequency of an infrared laser.
In contrast, direct-emission green laser diode modules are small, robust and offer power stability over a wide operating temperature up to 50°C. Their high beam quality and low power consumption open up new possibilities as light sources, says the firm.
"By using a low-power, direct-emission green laser, it is possible to achieve the same or better visibility as a high-power red laser diode," says managing director Tony Pope. "This is because the human eye is most sensitive to green light, which appears brighter to the eye than red light of the same output power. This is obviously beneficial when laser safety classifications must be taken into consideration," he adds.
Because green light is more visible than red laser light of the same power output and laser safety class, the green lasers are particularly suitable for outdoor applications. Rangefinders and distance meters, such as those used by builders and surveyors, can be used over longer distances without losing beam quality and coherence.?
With what is claimed to be excellent beam quality, the new range of green laser modules is also suitable for optical imaging, and their small package size is advantageous for very compact designs. The new technology makes high colour rendering and contrast very achievable and enables fine details to be displayed, even over large distances, which is of interest to manufacturers of show lasers, says the firm. Other applications include machine vision, biotechnology and spectroscopy.
The green laser diode modules produce a high-quality elliptical beam at 520nm and offer high output stability, with optical output powers of up to 35mW.
With an operating voltage of 9V DC and a broad ambient operating temperature range from -10°C to +50°C, the new laser modules are energy-efficient, requiring an operating current of typically 140mA at 35mW and offering a long lifetime at continuous operation.
Robust and reliable with externally adjustable optics and self-contained drive electronics, the modules are static, surge and reverse-polarity protected and RoHS compliant. Mechanical dimensions are 53mm in length and 12mm in diameter. The housing material is anodized aluminium. Electrical connections are made via 300mm external flying leads.
