Tunable laser exceeds 3 dBm over 40-nm range
Researchers at Agility Communications (Santa Barbara, CA) reported a fiber-coupled time-averaged power from a tunable laser in excess of 3 dBm across a 40-nm tuning range and error-free 2.5-Gbit/s transmission over 200 km of standard single-mode fiber at the annual meeting of the IEEE Lasers and Electro-Optics Society in San Diego, CA last November. The device consisted of a sampled-grating distributed-Bragg-reflector laser monolithically integrated with an electroabsorption modulator and semiconductor optical amplifier (SOA). An offset quantum-well structure was used to integrate the laser and SOA active regions with the tuning and modulator sections of the device such that the active region of the modulator and the tuning sections of the laser used the same bulk quaternary waveguide. The radio-frequency extinction ratio for the transmission was greater than 10 dB, and the dispersion penalty was less than 0.3 dB at 1560 nm and less than 1.5 dB at 1530 nm. The dispersion penalty may be lowered in the short-wavelength end of the range with optimization of operating parameters for the electroabsorption modulator. Contact Gregory Fish at [email protected].
For the first time, an optical data link between satellites orbiting Earth was established in November 2001 using a laser beam as a signal carrier. The satellites were able to transmit images from space to the ground in real time, promising much more timely delivery of data in the future.