The present invention provides systems and methods that employ a
continuously variable optical delay line to introduce a delay into a
transmitted optical signal. The delay line comprises a holey fiber
configured in a spiral layout, wherein one end of the fiber is operative
to a reflective fluid reservoir and the other end in operative to an
input port. A segmented piezoelectric actuator is employed to position a
reflective fluid within the fiber, utilizing a commutated technique that
continuously moves the fluid. A signal received at the input port is
routed through the holey fiber at an angle of incidence to achieve total
internal reflection. The signal traverses towards the reflective fluid,
and reflects back towards the input port after coming into contact with
the fluid's surface. The delay introduced into the signal is a function
of the distance traveled through the delay line.