Broadband Lasers Based
on Qdot Technology

NL Nanosemiconductor, a Germany-based maker of laser semiconductor chip and modules, said it has developed a laser chip that will enable cost-effective wavelength division multiplex (WDM) approaches to optical communications using silicon photonic technology, including silicon-based arrayed waveguides (AWGs) and light modulators. A single-mode continuous (CW) laser with a spectral width of >20 nm and spectral wavelength between 1200 and 1320nm is being put into production at NL Nanosemiconductor's facilities in Dortmund, Germany.

Alexey Kovsh, COO at NL Nanosemiconductor, said, "The uniqueness of our laser is the width (25 nm) and uniform shape (less than 3 dB modulation at 0.5 nm resolution) of the spectrum in the lasing regime. Of further importance is the high reproducibility of the lasing spectrum shape. We managed to develop a way to get a laser to lase with a very wide emission spectrum, which is of course opposite to the fundamental nature of lasing -- at a very narrow spectrum."

Example of lasing spectrum of broadband qdot laser

Having a laser that delivers light with high power density over wide range of wavelength is clearly beneficial for future WDM silicon-photonic based solutions, since the output can be spectrally split with sufficient power for highly efficient networks using a single source laser, the company said in a statement. "The development of quantum dot, or qdot, broadband lasers has been focused mainly on this application. However, work is also being done to extend the lasing spectrum above 40 nm and looking for shorter-term market potential, which may include medical and military applications," it said.

NL Nanosemiconductor, which also has offices in San Jose, Calif., was originally a spinoff of Ioffe Physico-Technical Institute in St. Petersburg, Russia. Its mode-locked and high-power laser semiconductor chips and modules, with a wavelength range of 1.1 - 1.3 µms, have application in the medical, industrial, communications and computer markets.

Emerging applications for light sources with a broad spectrum include optical coherence tomography imaging systems, which typically use so-called superluminescence LEDs (SLED) or amplified spontaneous emission (ASE) sources, the company said. Another potential use of such devices may result from the introduction of silicon-based modulation technology, in which many parallel channels are pumped by one light source. NL said the main drawbacks of SLEDs include limited power and low efficiency.

Juergen Kurb, CEO of NL Nanosemiconductor, said various innovative laser products using quantum dot technology have been introduced, and an optical timing source for high-end processors and communications applications is under development.

"Such a broadband Laser is the latest of our innovations, and we anticipate interest in its use for wide range of applications besides the obvious WDM networks," Kurb said.

He said the company is focusing on extending the technology by realizing a so-called comb-laser, a laser chip that provides lasing simultaneously on different selected wavelengths with uniform intensity distribution, for even higher power density per one channel.

For more information, visit: www.nanosemiconductor.com

Broadband Lasers Based on Qdot Technology

Broadband Lasers Based
on Qdot Technology