[Study on spectral broadened characterization of cross phase modulation in photonic crystal fiber]

Spectrum broadening induced by cross phase modulation (XPM) was investigated by exploiting the optical time-division multiplexing (OTDM) data signal and continue wave probe light co-propagation in dispersion flattened high nonlinear photonic crystal fiber (PCF). The effects of wavelength drift of probe lights, polarization mismatch, total power and power ration of pump and probe light on the spectrum broadening were analyzed. The results show that good XPM effects can be obtained in 36 nm wavelength range when the total power is higher than 23 dB, power ration of pump and probe light is appropriate and with identical polarization. Furthermore, polarization independent XPM effect can be achieved by using the remainder birefringence of the PCF with the pump state of polarization (SOP) aligned at 45 degrees to the PCF principal axes. The obtained results in this paper would be helpful for research on ultrahigh-speed all optical signal processing devices exploiting the XPM in PCF for future photonics network.