Japan's QD Laser has developed a compact green laser that could energize the market for high-definition micro-projectors.

The laser, a working sample of which was demonstrated at this week's Ceatec exhibition in Japan, is just 5.6-millimeters in diameter and produces a pure green light of 532 nanometers.

Green has always been a challenge for laser makers, unlike red and blue light, which are much easier to produce, and so green has been a stumbling block towards the development of cheap small and light projectors.

QD Laser managed to generate green light by first developing a laser than emits infrared light at 1064nm, which is twice the wavelength of green light. The beam from the laser is then fed through a crystal to produce green light at the second harmonic frequency of 532nm.

Other features of the laser include a wide operating temperature and low power consumption, making it suitable for use in battery-powered and small electronics devices. QD Laser said it is suitable for use in projectors embedded in devices such as cell phones and laptop PCs.

QD Laser is planning mass production next year and the laser should cost around US$10, said Mitsuru Sugawara, the company's president and CEO, during an interview at Ceatec. That will make it significantly cheaper than the only other competitor on the market, a micro green laser from Corning, according to Sugawara.