Princeton Lightwave Claims Laser Record
The company says it has developed a 1550 nanometer distributed feedback (DFB) laser that delivers 340 milliwatts of output power into a singlemode optical fiber -- more than twice the previous record of 165mW for this type of laser, according to Swami Srinivasan, product line manager at Princeton Lightwave.
The record appears to hold up. PLI's results have been accepted as a postdeadline paper, to be presented here on Thursday, so its claims have been subjected to careful scrutiny by academic experts in the field.
But like all records, it needs to be put into context in order to understand its significance.
Today, DFB lasers are commonly used as dense wavelength-division multiplexing (DWDM) sources because they emit a "pure" wavelength. A DFB laser has a corrugated structure on top of the laser, which effectively filters its output (for more explanation see Distributed Feedback (DFB) Lasers). In doing this, some power is thrown away, so it's more difficult to get high powers out of this type of laser.
Commercial DFBs in the DWDM bands around 1550nm typically offer outputs of about 60mW maximum. Other types of laser at other wavelengths offer more power, but don't offer the right wavelength properties for DWDM sources. Srinivasan says the combination of high-power and narrow bandwidth are very attractive. "Here is a component that didn't exist before, that could potentially lead to applications that didn't exist before," he says.
It could be a source for free-space communications, which would favor the eye-safe wavelength of 1550nm, providing it has the power to send signals a long way, he says. It could be a source for metro networks -- throwing a huge amount of power down the fiber would remove the need for optical amplifiers in some situations. It could be a low-noise pump laser. It could be a compact source for coarse wavelength-division multiplexing (CWDM).
Indeed, the main reason for making the technology announcement was to get PLI's results out there under peoples noses and see where the opportunities are, says Srinivasan. Provided there is interest from system and subsystem vendors, PLI intends to ramp up production of the high-power DBF, called WaveHarp, in Q3 this year.
— Pauline Rigby, Senior Editor, Light Reading, http://www.lightreading.com