Fiber optical parametric polarizer

In this work, a fiber-optical parametric polarizer (FOPP), i.e., a polarizing device based on parametric amplification in optical fibers is demonstrated. This was achieved for both the signal and idler waves with 25 dB gain over a broad bandwidth using the strong polarization-dependent gain (PDG) of parametric amplifiers. The experimental values of the degree of polarization (DOP) calculated from the Stokes parameters are indicated above each sphere. The gain spectra are also plotted with the parametric gain and the signal OSNR in insets. The Poincaré sphere represents the three normalized Stokes parameters (S1,S2,S3) in unit radius. Results show that he DOP of the signal significantly increases with the parametric gain, which means that the signal is simultaneously polarization-pulled and amplified. The best signal DOP is reached for the maximum parametric gain of 25 dB while keeping an optical signal to noise ratio (OSNR) of 22 dB. The idler SOP is also efficiently pulled towards the pump polarization. These results are in excellent agreement with a theoretical approach based on parametric gain.