Raman-induced limits to efficient squeezing in optical fibers

TL;DR

This paper demonstrates a record polarization squeezing in optical fibers and shows that Raman effects impose fundamental limits on squeezing efficiency at high pulse energies, supported by experimental data and quantum simulations.

Contribution

It provides the first experimental evidence that Raman effects limit optical fiber squeezing at high energies, with record squeezing measurements and detailed analysis.

Findings

Record polarization squeezing of -6.8 dB achieved

Raman effects reduce squeezing at high pulse energies

Experimental results agree with quantum simulations

Abstract

We report new experiments on polarization squeezing using ultrashort photonic pulses in a single pass of a birefringent fiber. We measure what is to our knowledge a record squeezing of -6.8 +/- 0.3 dB in optical fibers which when corrected for linear losses is -10.4 +/- 0.8 dB. The measured polarization squeezing as a function of optical pulse energy, which spans a wide range from 3.5-178.8 pJ, shows a very good agreement with the quantum simulations and for the first time we see the experimental proof that Raman effects limit and reduce squeezing at high pulse energy.