As Rudolf with his glowing nose leads Santa’s reindeer herd, the Mode-Locked Laser (MLL) leads the photonic circuitry for the photon-pair generation by providing the pulsed light for feeding the optical circuit. TU/e in collaboration with SMART Photonics has developed a chip-based MLL on an InP platform. The laser works on the full “C-band” (i.e. 1550 nm band), providing pulse-trains with 2.5-ps time width and 2.5 GHz repetition rate, and with a peak-to-noise ratio in the emission region equal to 40 dB.

Four MLLs on an InP chip manufactured at SMART (left) and same MLLs installed on their packaging (right).