scholarly journals High-fidelity nano-FTIR spectroscopy by on-pixel normalization of signal harmonics

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lars Mester ◽  
Alexander A. Govyadinov ◽  
Rainer Hillenbrand
Keyword(s):  
Ftir Spectroscopy ◽  
Near Field ◽  
Scanning Probe ◽  
Background Suppression ◽  
High Fidelity ◽  
Efficient Suppression ◽  
Tip Position ◽  
Signal Normalization ◽  
Physical And Chemical ◽  
Theoretical Results

Abstract Scattering-type scanning near-field optical microscopy (s-SNOM) and Fourier transform infrared nanospectroscopy (nano-FTIR) are emerging tools for physical and chemical nanocharacterization of organic and inorganic composite materials. Being based on (i) diffraction-limited illumination of a scanning probe tip for nanofocusing of light and (ii) recording of the tip-scattered radiation, the efficient suppression of background scattering has been critical for their success. Here, we show that indirect tip illumination via far-field reflection and scattering at the sample can produce s-SNOM and nano-FTIR signals of materials that are not present at the tip position – despite full background suppression. Although these artefacts occur primarily on or near large sample structures, their understanding and recognition are of utmost importance to ensure correct interpretation of images and spectra. Detailed experimental and theoretical results show how such artefacts can be identified and eliminated by a simple signal normalization step, thus critically strengthening the analytical capabilities of s-SNOM and nano-FTIR spectroscopy.

scholarly journals Subwavelength Nanostructuring of Gold Films by Apertureless Scanning Probe Lithography Assisted by a Femtosecond Fiber Laser Oscillator

Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 536 ◽  
Author(s):  
Ignacio Falcón Casas ◽  
Wolfgang Kautek
Keyword(s):  
Fiber Laser ◽  
Near Field ◽  
Diffraction Limit ◽  
High Repetition Rate ◽  
Scanning Probe ◽  
Optical Methods ◽  
Laser Source ◽  
Gold Films ◽  
Laser Oscillator ◽  
Scanning Probe Lithography

Optical methods in nanolithography have been traditionally limited by Abbe’s diffraction limit. One method able to overcome this barrier is apertureless scanning probe lithography assisted by laser. This technique has demonstrated surface nanostructuring below the diffraction limit. In this study, we demonstrate how a femtosecond Yb-doped fiber laser oscillator running at high repetition rate of 46 MHz and a pulse duration of 150 fs can serve as the laser source for near-field nanolithography. Subwavelength features were generated on the surface of gold films down to a linewidth of 10 nm. The near-field enhancement in this apertureless scanning probe lithography setup could be determined experimentally for the first time. Simulations were in good agreement with the experiments. This result supports near-field tip-enhancement as the major physical mechanisms responsible for the nanostructuring.

scholarly journals Laser heating of scanning probe tips for thermal near-field spectroscopy and imaging

APL Photonics ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 021301 ◽  
Author(s):  
Brian T. O’Callahan ◽  
Markus B. Raschke
Keyword(s):  
Laser Heating ◽  
Near Field ◽  
Scanning Probe ◽  
Field Spectroscopy

Chemical Imaging With a Scanning Probe Microscope

1999 ◽  
Vol 5 (S2) ◽  
pp. 970-971
Author(s):  
Dmitri A. Kossakovski ◽  
John D. Baldeschwieler ◽  
J. L. Beauchamp
Keyword(s):  
Beam Quality ◽  
Near Field ◽  
Ambient Air ◽  
Chemical Imaging ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Visible Range ◽  
Spectrometric Analysis ◽  
Chemical Information ◽  
Near Field Scanning

Scanning Probe Microscopy (SPM) is a superb tool for topographical analysis of samples. However, traditional varieties of SPM such as Atomic Force, Scanning Tunneling and Near-field Scanning Optical Microscopy have limited chemical contrast capability. Recently, several advanced techniques have been reported which provide chemical information in addition to topographical data. All these methods derive advantage from combinations of scanning probe methodologies and some other, chemically sensitive technique. Examples of such approaches are: Near-field Scanning Raman Imaging, Near-field Scanning Infrared Microscopy and mass spectrometric analysis with laser ablation through fiber probes.In this contribution we report the development of a new method in this family of chemically sensitive scanning probe techniques: Laser Induced Breakdown Spectroscopy with Shear Force Microscopy, LIBS-SFM. Traditional LIBS experiments involve focusing a pulsed laser beam onto the sample and observing optical emission from the plasma formed in the ablation area. The emissions are mostly in the UV/visible range, and the signal is due to electronic transitions in excited atoms and ions in the plasma plume. The spectra are analyzed to identify chemical elements. The spatial resolution of LIBS is limited by the wavelength and beam quality of the laser used for ablation. The experiments may be conducted in vacuum, controlled atmosphere, or ambient air.

Investigation of the influence of the scanning probe on SNOM near-field images using rigorous simulations including the probe

2014 ◽  
Author(s):  
Markus Ermes ◽  
Stephan Lehnen ◽  
Karsten Bittkau ◽  
Reinhard Carius
Keyword(s):  
Near Field ◽  
Scanning Probe

scholarly journals Optical Fibre Micro/Nano Tips as Fluorescence-Based Sensors and Interrogation Probes

Optics ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 213-242 ◽  
Author(s):  
Simone Berneschi ◽  
Andrea Barucci ◽  
Francesco Baldini ◽  
Franco Cosi ◽  
Franco Quercioli ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Optical Fibre ◽  
Near Field ◽  
Optical Devices ◽  
Biochemical Sensors ◽  
Whispering Gallery ◽  
Biochemical Sensing ◽  
Nano Structures ◽  
Microscope Imaging ◽  
Physical And Chemical

Optical fibre micro/nano tips (OFTs), defined here as tapered fibres with a waist diameter ranging from a few microns to tens of nanometres and different tip angles (i.e., from tens of degrees to fractions of degrees), represent extremely versatile tools that have attracted growing interest during these last decades in many areas of photonics. The field of applications can range from physical and chemical/biochemical sensing—also at the intracellular levels—to the development of near-field probes for microscope imaging (i.e., scanning near-field optical microscopy (SNOM)) and optical interrogation systems, up to optical devices for trapping and manipulating microparticles (i.e., optical tweezers). All these applications rely on the ability to fabricate OFTs, tailoring some of their features according to the requirements determined by the specific application. In this review, starting from a short overview of the main fabrication methods used for the realisation of these optical micro/nano structures, the focus will be concentrated on some of their intriguing applications such as the development of label-based chemical/biochemical sensors and the implementation of SNOM probes for interrogating optical devices, including whispering gallery mode microcavities.

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