  Optical tweezers use laser light to trap and move microscopic particles in
space. Here we demonstrate a similar control over ultrashort light pulses, but
in time. Our experiment involves temporal cavity solitons that are stored in a
passive loop of optical fiber pumped by a continuous-wave "holding" laser beam.
The cavity solitons are trapped into specific time slots through a
phase-modulation of the holding beam, and moved around in time by manipulating
the phase profile. We report both continuous and discrete manipulations of the
temporal positions of picosecond light pulses, with the ability to
simultaneously and independently control several pulses within a train. We also
study the transient drifting dynamics and show complete agreement with
theoretical predictions. Our study demonstrates how the unique particle-like
characteristics of cavity solitons can be leveraged to achieve unprecedented
control over light. These results could have significant ramifications for
optical information processing.
