Abstract The effect of radiation forces at the interface between dielectric materials has been a long-standing debate for over century. Yet there so far only limited experimental verification in complete accordance with theory. Here we measure surface deformation air–water induced by continuous and pulsed laser excitation match this to rigorous theory forces. We demonstrate that results are quantitatively described numerical calculations Helmholtz force is used pressure. resulting pressure...

Atomic force microscopy–infrared spectroscopy (AFM-IR) is a photothermal scanning probe technique that combines nanoscale spatial resolution with the chemical analysis capability of mid-infrared spectroscopy. Using this hybrid technique, identification down to single molecule level has been demonstrated. However, mechanism at heart AFM-IR, transduction local heating cantilever deflection, still not fully understood. Existing physical models only describe process in few special cases but many...

Eosin Y is known to be a powerful probe of biological molecules and an efficient photosensitizing agent for the production singlet molecular oxygen. Under continuous laser excitation, degradation through photobleaching observed in aqueous solutions eosin Y; this process driven by Optical bleaching yield anomalous thermal lens transient signals, which can evaluated modeling relaxation processes that give rise generation heat solution. A model describing signal derived applied investigate at...

Introduction of photothermal mirror spectroscopy employing a highly tunable mid-IR pump laser (PTM-IR) for the chemical analysis polystyrene thin film samples on IR transparent calcium fluoride substrates.

Abstract Electromagnetic momentum carried by light is observable through the mechanical effects radiation pressure exerts on illuminated objects. Momentum conversion from electromagnetic fields to elastic waves within a solid object proceeds string of electrodynamic and elastodynamic phenomena, collectively bound energy continuity. The details this predicted theory have yet be validated experiments, as it difficult distinguish displacements driven those heating due absorption. Here, we...

Abstract Laser-based mid-infrared (mid-IR) photothermal spectroscopy (PTS) represents a selective, fast, and sensitive analytical technique. Recent developments in laser design permits the coverage of wider spectral regions combination with higher power, enabling for qualitative reconstruction broadband absorption features, typical liquid or solid samples. In this work, we use an external cavity quantum cascade (EC-QCL) that emits pulsed mode region between 5.7 6.4 µm (1770–1560 cm −1 ), to...

This work presents a theoretical study of heat transfer effect, taking into account the within heated sample and out to surrounding medium. The analytical solution is used model thermal lens mirror effects results are compared with finite element analysis (FEA) software solution. FEA modeling were found be in excellent agreement solutions. Our also show that between surface air coupling fluid does not introduce an important effect over induced phase shift when obtained without considering...

A theoretical and experimental study taking sample-fluid heat coupling into account in time-resolved photothermal mirror experiments is presented. Thermoelastic equations were solved to obtain a semi-analytical solution the phase shift induced by sample surrounding fluid. The was used model thermal effects found be excellent agreement with finite element method analysis experiment. Heat transferred air-coupling fluid did not introduce important when compared obtained, without considering...

Abstract We induce nanometer-scale surface deformation by exploiting momentum conservation of the interaction between laser light and dielectric liquids. The effect radiation force at air-liquid interface is quantitatively assessed for fluids with different density, viscosity tension. imparted pressure on liquids continuous or pulsed excitation fully described Helmholtz electromagnetic density.

The time-resolved thermal mirror technique is developed under pulsed laser excitation for quantitative measurement of and mechanical properties opaque materials. Heat diffusion thermoelastic equations are solved analytically assuming surface absorption an instantaneous pulse. Analytical results the temperature change displacement in sample compared to all-numerical solutions using finite element method analysis accounting pulse width geometry. Experiments performed that validate theoretical...

Biodiesel susceptibility to oxidation is one of the major problems concerning its use as an alternative diesel fuel. Although well-characterized, process cannot be completely prevented since it can affected by a large number factors, such fuel composition, storage conditions, contaminants, temperature, and presence air light. In this work, we propose Fourier transform infrared spectroscopy (FTIR) in association with principal components analysis (PCA) hierarchical cluster (HCA) method for...

We propose a combined thermal lens and mirror method as concurrent photothermal techniques for the physical characterization of polymers. This is used to investigate polymers function temperature from room up 170 °C. The permits direct determination diffusivity conductivity. Additional measurements specific heat, linear expansion, temperature-dependent optical path change are also performed. A complete set thermal, optical, mechanical properties polycarbonate poly (methyl methacrylate)...

A three-dimensional time-resolved theory and experiment for photothermal deflection spectroscopy is developed. The heat conduction equations two semi-infinite media consisting of an opaque sample a fluid are solved considering temperature energy flux balance conditions Gaussian source. time dependent perpendicular signal calculated compared to experimental measurements on glassy carbon copper samples. Excellent agreement with literature values thermal diffusivity the samples found. transient...

The surface displacement produced by radiation pressure and electrostriction forces is investigated considering the commonly accepted theories proposed Minkowski Abraham for energy-momentum tensor. contributions are modeled each effect separately assuming non-absorbing absorbing solids thermoelastic deformation equations solved numerically. We show that profiles as calculated or momenta give different curvature, which could in principle be detected measuring displacement. Finally, an...

A theoretical model for a time-resolved photothermal mirror technique using pulsed-laser excitation was developed low absorption samples. Analytical solutions to the temperature and thermoelastic deformation equations are found three characteristic pulse profiles compared finite element analysis methods results An analytical expression intensity of center continuous probe laser at detector plane is derived Fresnel diffraction theory, which allows modeling experimental results. Experiments...

We investigate the thermoelastic waves launched by a localized heat deposition. Pulsed laser excitation is used to generate mechanical perturbations in metals that are detected using photothermal mirror method. This method detects wavefront distortion of probe beam reflected from perturbed sample surface. Nanometer scale expansion material induced just under irradiated surface releasing transient much smaller amplitudes on Numerical predictions and experimental results good agreement...

Atomic force microscopy-infrared spectroscopy (AFM-IR) is a photothermal scanning probe technique that combines nanoscale spatial resolution with the chemical analysis capability of mid-infrared spectroscopy. Using this hybrid technique, identification down to single molecule level has been demonstrated. However, mechanism at heart AFM-IR, transduction local heating cantilever deflection, still not fully understood. Existing physical models only describe process in few special cases but many...

Atomic force microscopy-infrared spectroscopy (AFM-IR) is a photothermal scanning probe technique that combines nanoscale spatial resolution with the chemical analysis capability of mid-infrared spectroscopy. Using this hybrid technique, identification down to single molecule level has been demonstrated. However, mechanism at heart AFM-IR, transduction local heating cantilever deflection, still not fully understood. Existing physical models only describe process in few special cases but many...

Abstract Edible vegetable oils are sources of polyunsaturated fatty acids, necessary for a balanced diet capable providing elements that act on the energetic, structural, and hormonal composition humans. The growing consumption these foods has encouraged search techniques characterizing their compositions transformations when subjected to industrial processes or during domestic use. We propose analyze undergone by edible originating from different plants due thermal oxidation. For this,...

Strong light absorption and high levels of singlet oxygen production indicate erythrosin B as a viable candidate photosensitizer in photodynamic therapy or inactivation microorganisms. Under irradiation, undergoes photobleaching process that can decrease the oxygen. In this paper, we use thermal lens spectroscopy to investigate micellar solutions ester derivatives: methyl, butyl, decyl esters low concentrations non-ionic aqueous solutions. Using previously developed model, it was possible...

Analytical and finite element analysis modeling methods of the pulsed-laser excited photothermal (PT) lens signal solids samples surrounded by air are presented. The analytical solutions for temperatures induced in sample were found to agree over range conditions this report. Model results show that contribution total PT is significant many cases. In fact, these open up possibility applying pulsed thermal method accurate prediction heat transfer coupling fluid subsequently study gas...