Optical injection locking-based amplification in phase-coherent transfer of optical frequencies

Abstract

© 2015 Optical Society of America. We demonstrate the use of an optical injection phase locked loop (OIPLL) as a regenerative amplifier for optical frequency transfer applications. The optical injection locking provides high gain within a narrow bandwidth ( < 100 MHz) and is capable of preserving the fractional frequency stability of the incoming carrier to better than 10 -18 at 1000 s. The OIPLL was tested in the field as a mid-span amplifier for the transfer of an ultrastable optical carrier, stabilized to an optical frequency standard, over a 292 km long installed dark fiber link. The transferred frequency at the remote end reached a fractional frequency instability of less than 1 × 10 -19 at averaging time of 3200 s.