Low noise mid-infrared supercontinuum generation in multimode chalcogenide fiber (Conference Presentation)

Abstract

We demonstrate the generation of a low-noise, octave-spanning mid-infrared supercontinuum from 1700 to 4800 nm by injecting femtosecond pulses into the normal dispersion regime of a multimode step-index chalcogenide fiber with 100 µm core diameter. We conduct a systematic study of the intensity noise across the supercontinuum spectrum and show that the initial fluctuations of the pump laser are at most amplified by a factor of three. We also perform a comparison with the noise characteristics of an octave-spanning supercontinuum generated in the anomalous dispersion regime of a multimode fluoride fiber with similar core size and show that the all-normal dispersion supercontinuum in the multimode chalcogenide fiber has superior noise characteristics. Our results open up novel perspective for many practical applications such as long-distance remote sensing where high power and low noise are paramount.

Perspective on the next generation of ultra-low noise fiber supercontinuum sources and their emerging applications in spectroscopy, imaging, and ultrafast photonics

“…The superior coherence and noise properties of ANDi SCs over conventional SCs were verified, for example, by measurements of relative intensity noise (RIN), spectral coherence, dispersive Fourier transformation, and RF beating with stabilized laser diodes 45,51,65 . ANDi SC also possess a remarkable resistance against technical pump laser fluctuations 54,64,66 , while conventional SCs amplify such fluctuations by up to 20 dB, even in the regime where coherent dynamics dominate 62 . Describing incoherent nonlinear dynamics in terms of the MPR gain is therefore a successful concept for explaining the superior stability of ANDi SC.…”