High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses

We demonstrate an effective microspectroscopy technique by tracing the dispersion of second order nonlinear optical susceptibility χ(2) in single atomic layer materials. The experimental method relies on the detection of single-shot second harmonic (SH) spectra from the materials and the subsequent...

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Main Authors: M. Mokim, A. Card, F. Ganikhanov
Format: Article
Language:English
Published: Elsevier 2019-01-01
Series:MethodsX
Online Access:http://www.sciencedirect.com/science/article/pii/S2215016119301037
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author M. Mokim
A. Card
F. Ganikhanov
author_facet M. Mokim
A. Card
F. Ganikhanov
author_sort M. Mokim
collection DOAJ
description We demonstrate an effective microspectroscopy technique by tracing the dispersion of second order nonlinear optical susceptibility χ(2) in single atomic layer materials. The experimental method relies on the detection of single-shot second harmonic (SH) spectra from the materials and the subsequent data normalization. The key point in our study is that we used a broadband (˜350 nm) near-infrared femtosecond continuum pulses generated at high repetition rates in a photonic crystal fiber with superior spatial quality and stable spectral power density. This is opposite to the point-by-point laser tuning method in SH generation spectroscopy that was applied extensively in the past and has shown limited precision in obtaining χ(2) dispersion. The continuum pulse technique produces spectral resolution better than 2 meV (<0.3 nm at 450 nm) and shows low (<5–6% rms) signal detection noise allowing the detection of subtle features in the χ(2) spectrum at room temperatures. Fine sub-structure features within the main peak of χ(2) spectra indicate the impact of broadened resonances due to exciton transitions in the single layer materials.• Tailored continuum pulses are used to generate second harmonic signal in non-centrosymmetric semiconductors.• SHG spectrum carries fingerprints of the bandstructure around the direct gap states.• The technique produces fine spectral resolution and much better signal-to-noise ratio compared to point-by-point wavelength tuning methods. Method name: Spectroscopy with continuum pulses, Keywords: Second harmonic generation spectroscopy, Optical nonlinearity in semiconductors, Broadband continuum
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spelling doaj.art-b309adc2937a427bbe8a1e465fe273ea2022-12-21T19:04:18ZengElsevierMethodsX2215-01612019-01-016910917High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulsesM. Mokim0A. Card1F. Ganikhanov2Department of Physics, University of Rhode Island, 2 Lippitt Road, Kingston, RI 02881, USADepartment of Physics, University of Rhode Island, 2 Lippitt Road, Kingston, RI 02881, USACorresponding author.; Department of Physics, University of Rhode Island, 2 Lippitt Road, Kingston, RI 02881, USAWe demonstrate an effective microspectroscopy technique by tracing the dispersion of second order nonlinear optical susceptibility χ(2) in single atomic layer materials. The experimental method relies on the detection of single-shot second harmonic (SH) spectra from the materials and the subsequent data normalization. The key point in our study is that we used a broadband (˜350 nm) near-infrared femtosecond continuum pulses generated at high repetition rates in a photonic crystal fiber with superior spatial quality and stable spectral power density. This is opposite to the point-by-point laser tuning method in SH generation spectroscopy that was applied extensively in the past and has shown limited precision in obtaining χ(2) dispersion. The continuum pulse technique produces spectral resolution better than 2 meV (<0.3 nm at 450 nm) and shows low (<5–6% rms) signal detection noise allowing the detection of subtle features in the χ(2) spectrum at room temperatures. Fine sub-structure features within the main peak of χ(2) spectra indicate the impact of broadened resonances due to exciton transitions in the single layer materials.• Tailored continuum pulses are used to generate second harmonic signal in non-centrosymmetric semiconductors.• SHG spectrum carries fingerprints of the bandstructure around the direct gap states.• The technique produces fine spectral resolution and much better signal-to-noise ratio compared to point-by-point wavelength tuning methods. Method name: Spectroscopy with continuum pulses, Keywords: Second harmonic generation spectroscopy, Optical nonlinearity in semiconductors, Broadband continuumhttp://www.sciencedirect.com/science/article/pii/S2215016119301037
spellingShingle M. Mokim
A. Card
F. Ganikhanov
High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
MethodsX
title High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
title_full High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
title_fullStr High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
title_full_unstemmed High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
title_short High spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
title_sort high spectral resolution second harmonic generation microspectroscopy at thin layer interfaces with broadband continuum pulses
url http://www.sciencedirect.com/science/article/pii/S2215016119301037
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AT fganikhanov highspectralresolutionsecondharmonicgenerationmicrospectroscopyatthinlayerinterfaceswithbroadbandcontinuumpulses