MARCH 23, 2010 – At OFC/NFOEC 2010, Furukawa Electric Co. Ltd. and the Specialty Photonics Division of OFS have announced the availability of a narrow linewidth full-band tunable laser, a coherent mixer with built-in polarization multiplexer/demultiplexer, and a polarization maintaining fiber with a new stress rod design for application in optical digital coherent transmission systems.
Furukawa has developed a tunable distributed feedback (DFB) laser with a linewidth less than 500 KHz, decreasing the linewidth of conventional DFB technology by a factor of 3 with an output optical power of 40 mW or higher.
In order to generate ultra-high-speed transmissions in an optical digital coherent system, system designers use a combination of a polarization multiplexer/demultiplexer and an optical interference device in a dual polarization quadrature phase shift keying (DP-QPSK) receiver.
Furukawa's planar lightwave circuit (PLC) technology has been applied into this new coherent mixer now integrated with a built-in polarization Mx/Dmx to improve the performance of DP-QPSK transmission. The result, says a company representative, is a smaller size, while maintaining loss uniformity (lower than 1 dB), low skew (typically lower than 1 ps), and high polarization extinction ratio (higher than 18 dB).
In the DP-QPSK modulation system, optical signals have to be transmitted while keeping the state of polarization. It can occur between an optical local oscillator and a coherent mixer or between a signal light source and a modulator.
Furukawa and OFS is exhibiting at OFC/NFOEC, booth #1023.