Both Mitsubishi and Samsung have planted stakes in the ground to add new vigor to the microdisplay-based rear-projection TV segment by promising to introduce sets with laser sources by Christmas 2007. The idea is to replace the arc lamp, which has a limited lifetime and difficulties in illuminating very small panels, with a laser source, which overcomes both of these issues. In addition, laser TVs can offer the best color gamut of any TV available, so lasers will appeal to consumers on several levels.

Chris Chinnock
Sr. Analyst and Sr. Editor
of Insight Media

But to get there, the major hurdle is the availability of red, green and blue lasers with the right wavelengths, power levels and price point. This is not an easy task as laser developers have never tried to produce such products in the past, and producing them in high volumes will require considerable effort.

There are a number of laser developers working on this issue, but the most visible one is Novalux. Today, they announced a milestone in their commercialization path that will make TV makers happy and add confidence to their plans to offer Laser TVs.

The milestone that Novalux reached is the achievement of 750mW of red laser output power and 3W of green and blue laser power. All devices are based on the company’s Necsel technology that features an infrared semiconductor laser and doubling crystal to achieve the desired RGB wavelengths. The demonstration of 3W green and blue lasers doubles the output power of previous devices. The 750mW red laser is the first one demonstrated using the Necsel architecture.

Novalux’s Greg Niven stated that its customers want 3W per color of laser light for their home theater TV products. According to Insight Media analyst Matthew Brennesholtz, who is the principle author of the "Laser Projection Display Report", 2W per color is the minimum level needed for a 50-inch RPTV. "Having 3W per color allows developers to offer bigger screen sizes and screens with lower gains. Lower gain screens are desirable not only for the wider viewing angles but also to help reduce speckle."

Niven stated that the development of the 750mW red laser was a good sign that it will soon reach the desired 3W level too. In previous demonstrations of its laser TVs, Novalux has used edge-emitting semiconducting laser with a wavelength of about 635nm. However, according the Brennesholtz, the optimal range of red wavelengths is between 615 and 626nm. Novalux’s new Necsel laser operates at 620nm - right in the middle of the sweet spot. This wavelength is actually fairly critical as moving to 650nm sources for example, more than doubles the required power to produce the same white point compared to a 620nm red laser.

Laser TV developers also desire the same laser device technology be used for all three colors to avoid potential differential aging issues and to reduce costs by have a common set of components and drive electronics. The green Necsel laser operates at 532nm while the blue runs at 465nm - both desirable wavelengths.

Novalux says its ultimate aim is to enable home theater systems that produce high-brightness, high-resolution images with over 200% of NTSC color coverage in a thin, wide viewing angle architecture. Many are watching the company to see if it can fulfill its big promise. So far, so good. -CC