Rapid ultrafine-tunable optical delay line at the 1.55-mu m wavelength

A fast, ultrafine-tunable delay line at 1550 nm is demonstrated by use of a cousto-optic pulse shaping. Delays of up to 30 ps can be achieved without a ny optical readjustment. The delay is linear to the rf center frequency app lied to the acousto-optic modulator and is fully electronic. It takes only 3 mu s to switch between different time slots, irrespective of the time sep aration in the tuning range of 30 ps; for a smaller tuning range the tuning speed can be faster. The tuning resolution and range depend on the choice of system parameters. The pulse energy can be regulated by rf power. (C) 19 98 Optical Society of America.