K. Tsuji et al., Polarization-independent wavelength conversion using four-wave mixing in single-mode fibers pumped with cross-polarized high frequency pulses, IEICE TR EL, E84C(5), 2001, pp. 564-570
This paper describes a simple polarization-independent wavelength conversio
n method using degenerated four-wave mixing (FWM) in single-mode fibers pum
ped with cross-polarized high frequency, saw-tooth pulses from a single pum
p source. Successful polarization-independent wavelength conversion is expe
rimentally confirmed with less than +/-12% and +/-5.6% variation using a ga
in-switched LD pumping and a mode-locked fiber laser pumping, respectively.
We clarify that the interference effect between two orthogonal pump pulses
must be taken into account to achieve a good polarization-insensitive oper
ation, since even the small pulse edges bring about the large polarization
fluctuations when they are interfered. Furthermore, it is reveal that the s
horter pump pulse broadens its own spectrum due to the self-phase modulatio
n in fibers, resulting in poor FWM efficiency. Finally, possibility of high
-speed operation is discussed taking into account the pump pulse conditions
.