Noise reduction of supercontinua via optical feedback.

The impact of delayed optical feedback on the supercontinuum noise properties is investigated numerically and experimentally. The supercontinuum is generated by coupling femtosecond laser pulses into a microstructured fiber within a ring resonator, which introduces the optical feedback. The power noise and spectral amplitude noise properties of this feedback system are numerically and experimentally compared with single-pass supercontinuum generation. In a demonstrative experiment via optical feedback the power noise could be reduced by 15 dB and the spectral amplitude noise could be reduced by up to 28 dB.

Adjustment of supercontinua via the optical feedback phase--experimental verifications.

The manipulation of a supercontinuum via delayed optical feedback is investigated experimentally. The supercontinuum is generated in a microstructured fiber and a feedback ring resonator introduces the optical feedback and leads to the formation of different regimes of nonlinear dynamics. Via the feedback phase the optical spectrum and the regimes of nonlinear dynamics can be adjusted systematically. The impact of delay detuning on two different length scales, namely on a sub-wavelength scale and on a larger scale in the order of 10 µm are discussed. Additionally, the adjustment of the optical spectrum without changing the regime of nonlinear dynamics is demonstrated.

Adjustment of supercontinua via the optical feedback phase - numerical investigations.

The delay and phase dependent behavior of a system for supercontinuum generation by using a microstructured fiber within a synchronously pumped ring resonator is presented numerically. The feedback introduced by the resonator led to an interaction of the supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. Via the feedback phase different regimes of nonlinear dynamics, such as steady state, period multiplication, limit cycle and chaos can be adjusted systematically. The spectrum within one regime of nonlinear dynamics can additionally be modified independently from the regime of nonlinear dynamics.

Experimental investigations on nonlinear dynamics in supercontinuum generation with feedback.

A system for supercontinuum generation by using a photonic crystal fiber within a synchronously pumped ring cavity is presented. The feedback led to an interaction of the generated supercontinuum with the following femtosecond laser pulses and thus to the formation of a nonlinear oscillator. The nonlinear dynamical behavior of this system was investigated experimentally and compared with numerical simulations. Steady state, period doubling and higher order multiplication of the repetition rate as well as limit cycle and chaotic behavior were observed in the supercontinuum generating system.

Nonlinear dynamics of femtosecond supercontinuum generation with feedback.

We numerically study the impact of feedback on supercontinuum generation within a microstructured fiber inside a ring resonator, synchronously pumped with femtosecond pulses. In certain parameter ranges we observe a steady-state oscillator-like operation mode of the system. Depending on pump power also period doubling up to chaos is shown by the system. Even with the inclusion of realistic pump noise as perturbation, the periodic behavior was still achievable in numerical modeling as well as in a first experimental verification.