Abstract:
The thermal effect of weak laser infrared radiation at a local point of the HgCdTe layer of the complex heterostructure (013)HgCdTe/CdTe/ZnTe/GaAs was studied with simultaneous measurement of the second harmonic signal using the null method “on reflection”. The exposure power was 0.8 mW in a laser beam 400 $\mu$m in diameter during the irradiation time of 15 minutes. The splitting of the second harmonic signal in the maxima was observed with the appearance of two additional peaks. With an increase in exposure time to 15 minutes, the magnitude of the second harmonic signal at the initial maximum decreased to the magnitude of the measurement system noise, with the simultaneous increase of the height of additional peaks from 3000 to 6000 counts unit. After the end of the laser exposure, the second harmonic form is restored to original form with a decrease in their magnitude to 1700–2200 counts unit. The temperature at the point of exposure was measured using a thermal imager and was 24.0$^\circ$C at the beginning of the measurements, and 24.6$^\circ$C at the end of exposure.
Keywords:stress, HgSdTe, second harmonic, laser, null method.
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