Athermal chirp-compensated directly modulated PIC for uncooled DWDM

The authors employ a novel PIC to demonstrate athermalised transmission under direct modulation. The unique architecture of the chip enables compensation of thermal redshift of laser wavelength through control of self-heating. The PIC consists of 2 lasers in a master-slave configuration. Such a structure improves the performance of a free running laser (slave) by optical injection from another laser (master). The benefits reaped from such a PIC structure implementing optical injection include chirp minimisation, linewidth reduction, and improved modulation response. Experimental demonstration of 2.5 Gb/s OOK data transmitted over 37 km with error-free performance over the temperature range 10-45°C is presented.