I came across this article and thought it may be relevant. I don't fully understand the technical side but am curious whether it is presents an advancement that would be competition or something MVIS would or could incorporate? The last sentence in the last paragraph caught my attention (my bolding).
news.photonicsonline.com
T O D A Y ' S N E W S A N D A N A L Y S I S...
Tech Briefs: Blue Laser Produces 7.3 W of Output
Titanium-doped sapphire laser incorporates beta barium borate as the
doubling crystal to generate 7.3 W of output at 446 nm for laser
projector applications.
By: Kristin Lewotsky
Laser-based projection displays can produce highly visible images even in bright light. The greater the output power of the lasers used to generate the image, the brighter, the resultant picture. By optimizing the cavity length in a doubled titanium-doped sapphire (Ti:sapphire) laser, Andrew Radl and team members at the Corporation for Laser Optics Research (COLOR; Portsmouth, NH) produced more than 7.3 W of TEM00 output at 446 nm.
They believe this to be the highest output power produced in the blue
spectral region by a Ti:sapphire system to date. "This is a very significant breakthrough," said Stephen Benton of the Massachusetts Institute of Technology (MIT; Cambridge, MA) “Attempts at producing blue light are usually measured in tens of milliwatts.”
System design
A flashlamp-pumped neodymium-doped yttrium aluminum garnet (Nd:YAG)
laser provides the pump energy for the Ti:sapphire laser. Previously, the team had succeeded in coaxing 5 W of output in the blue spectral region (430 nm to 450 nm) from their system, which was doubled using a single intracavity beta barium borate (BBO) crystal. According to director of optical engineering Robert Martinsen, to achieve higher powers, the group initially turned to a walk-off-compensated, two-crystal, intracavity approach, incorporating BBO. In initial experiments, the system produced 7.1 W of output, an increase of nearly 30%. “We thought [the improvement] was the result of walkoff compensation,” said Martinsen. “Then we revisited how much we could get with one crystal if we paid attention to optimizing crystal length, and lo and behold, we got 7.3 W.”
The system is tunable from 430 nm to 450 nm, with peak performance at
446 nm. With an M2 of 1.8, the laser produces elliptical TEM00 output; the elliptical character is introduced by the beam walkoff introduced by the BBO. “Now we're revisiting the walkoff compensation scheme,” said Martinsen, who is confident that the team can beat 7.3 W with the
dual-crystal configuration.
The future
The current system is just one part of the work underway at the company, however. One project focuses on the development of a diode-pumped, all-solid-state system, based on a diode-pumped neodymium-doped vanadate laser as the Ti:sapphire pump source. The team is also focusing on other methods for generating the necessary output. “We're working on a more direct approach to going to blue,” said Martinsen, though he declined to offer details.
COLOR produces video-rate laser projection systems for military and
entertainment applications. The galvo-scanned systems typically incorporate Ti:sapphire for blue output, Nd:YAG for green output, and dye lasers or diode lasers for red output. The displays are so bright that even with floodlights trained on the screen, a viewer can still see the image. The shift to DPSS technology will allow the company to offer more compact, robust systems that will be more cost-competitive with other technologies.
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