Beam Shaper Makes Square Laser Light Round

Schott is introducing beam-shaping technology at Photonics West 2007 which it said offers laser users a simple and efficient way to shape “square” light from an individual laser diode or rows of laser diode strings into a beam of light that has a round profile and offers homogeneous light dissemination.

Its Beam Shaper achieves this using bundled glass fibers that direct light in the desired direction. Until now, Schott said, round, homogeneous laser beams could only be achieved using optics consisting of lenses and mirrors that are complex and difficult to adjust.

The Beam Shaper will be offered in two different versions: For individual laser diodes with outputs of up to one watt, the Beam Shaper will be cylindrical. For bars consisting of dozens of laser diodes with a total output of tens of watts,it will be equipped with a paddle-shaped end that matches with the geometry of the diode bar.

Both versions of the Beam Shaper provide a high output of 90 percent. However, the Beam Shaper offers laser users other benefits as well.

“The Beam Shaper simplifies the assembly,” said Burkhard Danielzik, general manager, business development, for fiber optics at Schott. “This results in tangible economic advantages.”

Schott undertook research on the Beam Shaper because round lasers are needed for many applications. For example, physicians who use photoactivated drug therapies and DVD player manufacturers who use laser beams to write information onto silver disks both require lasers that produce points of light that are as round and homogeneous as possible. The Beam Shaper will allow these and other laser users to easily and efficiently produce round and homogenous laser beams.

While most customers need a light beam with a round profile, the Beam Shaper also enables laser users who need other beam geometries (oval cross-sections of various sizes for example) to produce the beam geometry they require.

Customers can use the Beam Shaper with lasers of various light wavelengths. Its rods of fiber optics can conduct wavelengths of light between 400 and 1700 nm.

In addition, the Beam Shaper is extremely tough. It can withstand temperatures of up to 663 °F (350 °C) and can also resist many types of chemicals.

Schott is also introducing to the North American market its new floating display technology, which uses glass fibers to make the images on LCD and OLED displays appear as if they are “floating” on top of the faceplate covering them. Currently, displays are usually covered by cheap plastic faceplates positioned a few millimeters above them. Schott said glass faceplates made with its floating display technology make text and images on these displays appear as if they are floating on top of the surface of the faceplate glass. The faceplates look much like conventional plastic and glass faceplates, but they are comprised of millions of 0.025-mm thin glass fibers that guide the light from the display to the viewer, making it appear as if the text and images on the display are floating on top of the faceplate, even though they are actually behind it. By guiding the light from the display, the technology also improves the visibility of the display in strong daylight.

“When people see this for the first time, they are absolutely amazed,” said Danielzik. “Companies will be able to use Schott’s floating display technology to produce displays that are more functional, more attractive and more stylish.”

Schott thinks the technology could be used to build better displays for various types of handheld devices and for other types of displays where readability, especially in daylight, is essential. For example, the background lighting used for automobile navigation systems and other automobile displays produce a lot of scattered light. This scattered light illuminates the car interior and makes it difficult to see outside the car at night. Floating display faceplates would reduce scattered light so that text and images only light up in the direction of the driver. This same optical effect would also enhance the readability of automobile displays in daylight and improve their brilliance and contrast, the company said.

Schott researchers have also developed a manufacturing technology for producing so-called fast axis collimation (FAC) lenses with a high degree of reproducibility, ensuring easy mounting and adjustments inside the laser. The lenses are manufactured using a special precision molding process. In combination with high refraction low Tg glasses, a numerical aperture of 0.8 can be achieved.

FAC microlenses are cylindrical lenses with an aspherical surface made of specialized optical glass. The lenses are increasingly important in building high-power diode lasers (wavelength range between 800 and 1000 nm). Thanks to a broadband antireflection coating, Schott achieves transmission > 0.99 for the relevant wavelength range. These lasers are used in many applications, including marking, printing, drilling, hardening, pumping, welding and cutting. Industries as varued as automotive, machine tooling of parts for many manufactured goods, and medical instruments and equipment will put them to work.

The Schott precision molding process is based on molds that have to be extremely precise. Their shape is duplicated up to thousands of times in glass, making the process reproducible and resulting in high lens quality and reliability. Even batches of more than 10,000 units can be produced with insignificant deviations in quality. The lenses can also be produced with bonded tabs for easier mounting to the laser bar.

For more information, visit: www.us.schott.com