Multiwavelength Frequency-Division-Multiplexed Light Source Based on Dispersion-Mode-Locking

Two dispersion-mode-locked laser experiments, each using a single, actively modulated linear optical amplifier and one or more fiber Bragg gratings, are presented. The first experiment demonstrates multiwavelength lasing based on dispersion-mode-locking. This mode-locking technique offers an intrinsic benefit that each wavelength is intensity modulated at a unique frequency, thus producing a frequency-division-multiplexed output. The second experiment shows fine-tuning of the dispersion-mode-locked lasing wavelength. Tunability from ~1546.5-1547 nm with a linewidth of ~0.06 nm was achieved. All experimental results should be applicable to other gain and dispersion media. A combination of the two experiments produces an excellent multiwavelength light source for sensing applications: for example, each of the multiple wavelengths can be tuned and locked to a gas absorption feature. The transmission at each wavelength can then be monitored using a single photoreceiver and a multichannel lock-in amplifier.