Compact brilliant laser light source developed

Scientists from Ferdinand-Braun-Institut have developed small, brilliant laser light sources that provide significantly smaller systems for laser projectors and other display technologies.

After watching a roller-coaster ride in a film, Dr. Katrin Paschke, head of a junior research group at the institute, felt sick to her stomach. The realistic pictures she viewed were produced by a specific projection technology.

“With laser projection, ninety percent of the color space of the human eye can be covered. Thus, the image quality is fascinating. Today’s flat screens manage only about fifty percent,” Paschke said.

Although they provide particularly realistic images, the laser projectors are too bulky in size. In flight simulators, for example, the laser system is the size of a cabinet, which considerably limits applications and explains why the technology has not yet been translated for use in home television sets.

Scientists are now looking for ways to develop smaller devices that can achieve high optical output powers in the watt range and produce excellent beam quality at the same time.

Paschke’s team has developed a red laser light source within InnoProfile, an initiative funded by the German Federal Ministry of Education and Research, and a development contract with LDT Laser Display Technology GmbH of Jena. LDT plans to integrate the matchbox-size laser modules into its next-generation laser projectors.

Scientists have developed a compact laser module for display technology that is no larger than a matchbox. Courtesy of ©FBH.

Combining several elements, the modules are composed of a laser chip and micro optics. A red light is generated directly by rice-grain-size semiconductor lasers. The laser chip, which trapezoidally broadens toward the opening, produces a high-quality beam because it can be generated compactly. It then enlarges in the tapered section. As a result, the high output powers can be spread over a comparatively broad opening of several hundred micrometers.

To render the radiation of the laser modules usable for laser projection, the beam must be collimated afterward, which means that it must be adjusted in parallel. An elaborated thermal management also ensures that the diode lasers can be operated under optimum thermal conditions of below 15 °C. To dissipate excessive heat, Paschke’s team used specifically manufactured industrial diamonds.

The tiny, brilliant laser light sources will ensure not only that pin-sharp pictures are generated in planetaria and flight simulators, but also that they will deliver more lifelike pictures into consumers’ living rooms, she said.

With high hopes for the entertainment industry, she expects that holograms will leap through our homes one day.