The sample beam was scanned by an X-Y scanner (Cambridge Technology, Cambridge, MA,) and was focused on the sample through an objective lens with 30mm focal length.
A part of energy of the evanescent wave is absorbed by the sample so that the IR beam energy is attenuated as being reflected to the detector.
The laser beam is focused using a lens of focal length 185 mm and the transmittance is measured using a pyroelectric energy probe as a function of sample position z by translating the sample along the beam axis (z-axis).
The signal beam reflected by the sample is recombined with the reference field and detected by one channel of a 6-channel spectrometer (Avantes, Inc., Broomfield, CO) which allows simultaneous detection of all 6 interference signals.
The intensity and the phase for the optical beam transmitted by the sample are calculated from the previous equation: In Fig. 2 O P L = Ψ λ / 2 π for a bovine spermatozoa, and preadipocyte 3T3-F442A mouse cells are displayed.
We note that the peaks for Si and Cr in the EDX spectrum stem from the glass substrate and a thin Cr layer, deposited on the sample to prevent charging of the sample by the electron beam in the SEM, respectively.
By rastering the sample through the fixed beam, we obtained an x-ray absorption map at the selected x-ray energy.
To make these images representative of experimental images, typical image distortions that are caused by instabilities of the sample and electron beam during experimental STEM image acquisition have been artificially introduced to these simulated images.
19 Because of the observed gradual, continuous decrease of PA signal during the irradiation of the sample by the laser beam, a well-defined measuring protocol was proposed and used consistently to quantify total carotenoids in flours.
In order to prevent crystallization by the electron beam, the samples were examined under low electron-dose illumination using the smallest condenser lens aperture (10 μm).
