Properties of CdTe thin films prepared by hot wall epitaxy

CdTe thin films were grown on different substrates: BaF₂ (111), polished Si (100), SiO₂, bulk CdTe (110) and HgxCd₁₋xTe layers by hot wall epitaxy (HWE). Chosen temperature parame-ters and technological process of thin film fabrication provided the growth rate of about 0.03 mm/min. The current-voltage characteristics and transmission spectra were measured. X-ray diffrac-tion data (XRD) measurements were carried out as well

Ground-state depletion for subdiffraction-limited spatial resolution in coherent anti-Stokes Raman scattering microscopy

We theoretically investigate ground-state depletion for subdiffraction-limited spatial resolution in coherent anti-Stokes Raman scattering (CARS) microscopy. We propose a scheme based on ground-state depopulation, which is achieved via a control laser light field incident prior to the CARS excitation light fields. This ground-state depopulation results in a reduced CARS signal generation. With an appropriate choice of spatial beam profiles, the scheme can be used to increase the spatial resolution. Based on the density matrix formalism we calculate the CARS signal generation and find a CARS signal suppression by 75% due to ground-state depletion with a single control light field and by using two control light fields the CARS signal suppression can be enhanced to 94%. Additional control light fields will enhance the CARS suppression even further. In case of a single control light field we calculate resulting CARS images using a computer-generated test image including quantum and detector noise and show that the background from the limited CARS suppression can be removed by calculating difference images, yielding subdiffraction-limited resolution where the resolution achievable depends only on the intensity used

Defect Profile Induced by Friction and Wear Processes Detected by Positron Annihilation Method

The positron annihilation studies of defect profile in Cu samples whose surfaces were exposed to the friction and wear processes are presented. The values of the S-parameter and its dependences on the depth from the Cu surface are the functions of the value of the load applied in the sliding contact between two metals. It indicates possibilities of applying the presented measurement method in the industry