Dispersion-induced bandwidth limitation of variabletrue time delay lines based on linearly chirped fibre gratings

Abstract

The electrical bandwidth limitation of continuous variable time delay units based on chirped fibre gratings is studied. The radiofrequency response of a linearly chirped fibre grating with an optical bandwidth of 4 nm and a dispersion of nearly 850 ps/nm has shown a –3 dB bandwidth of 6.4 GHz. To overcome this limitation, the use of a single-sideband plus carrier generator employing a dual-drive electro-optical modulator is experimentally demonstrated.