Photothermal cantilever excitation provides a fast and easy to implement means to control the deflection of standard atomic force microscopy cantilevers. Minute heat pulses yield deflections on the order of several tens of nanometers or when the deflection is kept constant, forces of several hundreds of piconewton can be applied. In our case these pulses resulted in less than 1 K temperature ch...

In this paper we will describe and compare different non destructive Photothermal Deflection methods easy to develop and not expensive which permit the determination of the thermal diffusivity of bulk semiconductor material. The first method consists to draw the experimental amplitude and phase of the photothermal deflection signal versus square root modulation frequency. The sample placed in a...

We modify the well-known photothermal beam deflection technique to study ultrafast nonlinearities. Using phase-sensitive detection we directly measure the temporal and polarization dynamics of nonlinear refraction (NLR) with sensitivity to optically induced phase changes of approximately λ/20,000. We use the relative polarization dependence of excitation and probe to separate the isotropic and ...

A time resolved measurement of the thermaly induced surface deformation has been carried out using visible light-based photothermal deflection technique. Thermal conductivity coefficients were determined for several semiconductor materials. Problems of the experimental data interpretation with respect to the effect of 2D/3D heat source excitation and the potential advantages of the time resolve...

The paper presents preliminary results of a study about the possibility to determine the thermoelastic properties of diamond-like carbon films by means of a photothermal deflection technique. The technique allows to perform measurements as a function of temperature in the range 10-300 K The results are in qualitative agreement with theoretical predicitons.

Visible light emitting diodes of three different colors have been used to detect an absorbing compound (potassium permanganate) in trace quantities in aqueous solution. Photothermal absorption in a closed cell caused deflection of a water meniscus held at a small pinhole. The displacement was monitored using optical fiber interferometry. The technique was limited by LED emission intensities and...

Complete statistical randomization of the direction of propagation of light trapped in semiconductor films can result in a large absorption enhancement. We have employed a calorimetric technique, photothermal deflection spectroscopy, to monitor the absorption of alpha-SiH(x) films textured by the natural lithography process. The observed enhancement factors, as high as 11.5, are consistent with...