Nonlinear optical characteristics of composite biosolders based on bovine serum albumin and single-walled carbon nanotubes

Composite biomaterial consists of bovine serum albumin 25 wt. % and single-walled carbon nanotubes <;0.3 wt. %. This material designed for laser welding of biological tissues. Nonlinear optical characteristics were studied for determination of influencing the threshold effects in this composite, which occur during interaction with powerful laser radiation. The quality of this biomaterial was determined by absorption specters and methods with the fixed location of the sample and Z-scan. We use radiation transfer equation for simulation of process of such nonlinear interaction. The solid-state Nd:YAG laser LS-2147 (LOTIS TII) was used for approbation of threshold model. It generated laser radiation with wavelength 532 nm and 1064 nm, pulse duration of 16 ns. It was found that critical value of the laser intensity of the appearance of non-linear optical properties was ~ 10 MW cm
^-2
with the thickness of the layer of composite biomaterial ~ 0.2 cm. Knowledge of the nonlinear optical characteristics of the composite biomaterial allows to determine the absorbed energy of the laser radiation with the help of threshold model. The control of the formation of a composite biomaterial can be performed knowing nonlinear optical characteristics, what in its turn allows to determine the energy of the laser radiation which has been absorbed by the sample. These studies show the possibility to control the process of formation a composite biomaterial from albumin aqueous dispersion of carbon nanotubes under the influence of laser radiation with a very small effect on the substance outside the radiation zone. These studies demonstrate the ability to control the formation of a composite biomaterial from the aqueous dispersion with bovine serum albumin and single-walled carbon nanotubes if it used the powerful laser radiation