학술논문

High Coherence at f and 2f of Mid-Infrared Supercontinuum Generation in Silicon Germanium Waveguides
Document Type
Periodical
Source
IEEE Journal of Selected Topics in Quantum Electronics IEEE J. Select. Topics Quantum Electron. Selected Topics in Quantum Electronics, IEEE Journal of. 26(2):1-8 Apr, 2020
Subject
Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Optical waveguides
Coherence
Dispersion
Bandwidth
Absorption
Silicon
Optical pulses
silicon germanium
silicon photonics
supercontinuum (SC) generation
Language
ISSN
1077-260X
1558-4542
Abstract
Absorption spectroscopy based on supercontinuum generation in the mid-infrared is a powerful technique to analyze the chemical composition of samples. Furthermore, phase-coherent supercontinuum sources can enable fast data acquisition with coherent, stable pulses that allow single-shot measurements. We report here a numerical study of the coherence of an octave-spanning mid-infrared supercontinuum source that was experimentally obtained in an air-clad SiGe/Si waveguide. We show that engineering two closely spaced zero-dispersion wavelengths that enclose an anomalous dispersion band centered around a fixed pump wavelength can produce supercontinuum pulses with high spectral density and full coherence at the extreme ends of the spectrum. This work is important for absorption spectroscopy, on-chip optical frequency metrology, and f -to-2 f interferometry applications.