Sluggish light for radio-frequency true-time-delay applications with a large time-bandwidth product.
A new radio-frequency (RF) photonic technique for achieving large RF time delays has been experimentally demonstrated using femtosecond pulses modulated by an acousto-optic tunable filter in a frequency-mapped and Doppler-shifted modulation scheme. A short optical delay line with length of 240 mum produces nearly 3 micros RF time delay after optical heterodyne detection, resulting in an effective slow-light velocity of 86 m/s. A delay-to-pulse-width ratio of 20 based on this technique has been observed, with a larger fractional delay foreseeable.
Gao
Lu
L
Optoelectronic Computing Systems Center, University of Colorado, Boulder, Colorado 80309, USA. lu.gao@colorado.edu
Herriot
Sandrine I
SI
Wagner
Kelvin H
KH