Abstract
Midinfrared absorption can be locally measured using a detection combining an atomic force microscope and a pulsed excitation. This is illustrated for the midinfrared bulk GaAs phonon absorption and for the midinfrared absorption of thin SiO(2) microdisks. We show that the signal given by the cantilever oscillation amplitude of the atomic force microscope follows the spectral dependence of the bulk material absorption. The absorption spatial resolution achieved with microdisks is around 50 nanometer for an optical excitation around 22 micrometer wavelength.
Highlights
The local measurement of midinfrared absorption with a nanometer scale resolution is a challenging issue
We show that the signal given by the cantilever oscillation amplitude of the atomic force microscope follows the spectral dependence of the bulk material absorption
We show that the oscillation amplitude of the atomic force microscope cantilever is directly correlated to the spectral dependence of the absorption
Summary
The local measurement of midinfrared absorption with a nanometer scale resolution is a challenging issue. Apertureless scattering scanning near-field microscopy has been demonstrated on various type of samples using an optical excitation delivered by a CO2 laser around 10.6 μm.[1, 2] The apertureless near-field microscope is based on the scattering of the electromagnetic field induced by the tip of an atomic force microscope (AFM) in tapping mode This scattering is dependent on the local value of the complex dielectric function. This technique was recently extended to far-infrared using free-electron laser pulses to image ferroelectric domains.[3] Midinfrared absorption can be measured using an atomic force microscope tip in contact mode as a sensor. A qualitative framework based on percutionnal mechanical excitation is proposed as a base for the discussion of the observed signal features
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
