Cross-Switching of C-Band Pulses in Dual-Core Soft Glass Fibers with Different Measure of Asymmetry

We present a comprehensive experimental investigation of dual-wavelength switching involving $1560 \mathrm{~nm}, 75 \mathrm{fs}$ pulses (referred to as signal) driven by $1030 \mathrm{~nm}, 270 \mathrm{fs}$ pulses (referred to as control) using two high index contrast dual-core fibers with different measure of dual-core asymmetry. Beside the asymmetry, the study explores the influence of fiber length and control pulse energy on the switching performance. In the case of fiber with higher asymmetry, we achieved an exceptional switching contrast of 41.6 dB at 14 mm fiber length, exhibiting a broadband character within the spectral range of 1450-1650 nm. In contrast, the fiber with lower asymmetry enabled a maximum switching contrast of 10.7 dB at 22 mm fiber length. According to our understanding the switching mechanism is driven by nonlinear balancing of dual-core asymmetry, therefore it took place at lower control pulse energy in the latter case. Our findings underscore the critical role of proper dual-core asymmetry in achieving efficient switching performance and have significant potential applications.