ELECTRICAL PULSE TRANFORMATION USING OPTICAL DELAY LINES

摘要

A recirculating optical delay line (30) has a laser (32) controlled bywavelength control (33) so as to vary the wavelengthof radiation over time to provide a first input (34) to an optical modulator(35). The modulator (35) modulates the intensityof the first input (34) with a pulsed electromagnetic frequency signal (36) toproduce a pulsed modulated optical signal (39). Thesignal (39) passes through an optical coupler (40) into a delay loop (41)having a delay fibre (44) arranged to delay the signal (39)for a predetermined duration. The wavelength control (33) is arranged to varythe first input (35) so as to ensure that overlappingpulses of the signal (39) in the delay loop (41) are at different wavelengths,thereby inhibiting optical mixing effects between theoverlapping pulses.