All-optical demultiplexing of 640 to 40 Gbits/s using filtered chirp of a semiconductor optical amplifier

We present a high-capacity ultrafast all-optical time demultiplexer that can be employed to retrieve 40 gigabits/second (Gb/s) base-rate channels from a $640\mathrm{Gb}∕\mathrm{s}$ single-polarized signal. The demultiplexer utilizes ultrafast effects of filtered chirp of a semiconductor optical amplifier. Excellent demultiplexing performance is shown at very low switching powers: $+8\mathrm{dBm}$ ($640\mathrm{Gb}∕\mathrm{s}$ data) and $-14\mathrm{dBm}$ ($40\mathrm{GHz}$ clock). The demultiplexer has a simple structure and, in principle, allows monolithic integration.