Gore Photonics Group demonstrates 1300 nm VCSEL

17 Jun 2002

Scientists at W.L. Gore and Associates' Gore Photonics Group have successfully demonstrated a 1300 nm Vertical Cavity Surface Emitting Laser (VCSEL).

The 1300 nm VCSEL provides power from 0 to 70 degrees Celsius and 2.5 V operating voltages. The VCSEL provides 5 mA threshold currents and can be modulated at data rates of a gigabit a second or more.

VCSEL technology, in which the laser emits light through the surface of the top, is not new, but the standard has been a wavelength of 850 nm. That's a good wavelength for some purposes, but not for others.

Creation of a 1300 nm VCSEL is difficult for a couple of reasons. Running current through the devices is not as easy as with the shorter wavelength VCSELs, and the need for a good mirror stack is another obstacle with the longer wavelengths.

The Gore Photonics Group has been working on the problem for over three years. "We've designed a way of using another laser, an 850 laser, as an optical pump, basically," said product engineer Richard Kriese.

A special fusion technology was used to solve the issue of the mirrors. "Effectively it gives us a 1300 nm output and avoids these problems," noted Kriese.

A 1300 nm VCSEL allows applications such as single-mode fiber and longer distance transmission, that is from 200 meters to 10 kilometers. The applications in wide-area networks, fiber-to-curb, and fiber-to-home lead the potential benefits.

"We're also excited about the advantages it offers in eye safety," said Kriese.

The 850 nm VCSEL is not seen by the human eye, so the intensity can burn the retina. Because the 1300 nm VCSEL has visible light, the effect is similar to looking into the sun: eye damage could occur if one is staring but the eye will naturally blink.

The increased eye safety allows for greater power output.

W.L. Gore doesn't expect to bring the VCSELs into commercial use until next year. "We're still working on the reliability data for the devices. It probably takes six months or so of exposure to high humidity and high temperature to see how they're going to do in the long run," said Kriese. "You just have to test it. It takes a while."

While the 1300 nm VCSEL is being tested for reliability, testing of other configurations is also part of the Gore Photonics Group development program. Placing 12 VCSELs next to one another within a couple of centimeters provides possibilities for high-speed computing applications.

Success at the 1300 nm level may also lead to development of VCSEL and VCSEL arrays at the 1550 nm wavelength, which would have applications in wavelength division multiplexing.