Visualization 1 KDobek.mp4

Visualization 1 presents operation of the thermal lens in imaging of the cross section of Tilia Stem. Initially the sample is at focus of the objective of the microscope with thermal lens inactive. Next, the sample is moved out of the focus, by increasing the distance of the sample from the microscope objective entrance window. Simultaneously, thermal lens focal power is continuously increased by rising power of the laser beam that forms the thermal lens (P). At a dz shift of the sample, at which only part of its image is sharp, the position of the heating laser beam is moved in the thermal lensing material resulting in a change in the position of the sharp part of the image. The laser beam returns to its initial position. Then, the effect of turning off/on the heating laser is shown. Finally, P is continuously lowered and reach P = 0.