Polarization Dependence of Modal Attraction in High Birefringence Bimodal Optical Fibers

We study nonlinear mode coupling among two intense and copropagating beams of different wavelength in bimodal and high birefringence optical fibers. With the proper design of the bimodal fiber, we show that this process may lead to modal attraction, where the modal distribution of light at a pump wavelength is replicated at the signal wavelength, independently of the input mode excitation conditions of the signal. We analyse the dependence of the efficiency of the modal attraction process upon the input state of polarization of both the signal and the pump beams.