We demonstrate for the first time, to the best of our knowledge, that a Sagnac interferometer can threshold the energies of pulses. Pulses below a given threshold T are suppressed, while those above this threshold are normalized. The device contains an in-loop tunable isolator and 10.4 m of a highly doped silica fiber. We derive an analytical model of the nonlinear optical loop mirror's pulse energy transfer function and show that its energy transfer function approximates a step function for very high phase shifts (>φ). We reveal some limitations of this approach, showing that a step-function transfer function necessarily results in pulse distortion in fast, nonresonant all-optical devices.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering