Photostability of Fiber-Optic Photoacoustic Transducer Based on Silver Nanoparticle Layer

A hybrid metal polymer based on polymethyl methacrylate with embedded metal nanoparticles

“…To estimate the cooling rates, 3D-simulating of the hybrid material was performed in the Comsol Multiphysics 5.5 environment. PMMA sample with metal particles embedded in it with radius of 50 nm was placed in the following conditions: temperature of metal nanoparticles is 375 K, temperature of the PMMA matrix and the environment (air and quartz glass substrate) is 293 K. The quartz glass substrate was chosen from the considerations that it is convenient to place the active medium of the optoacoustic converter directly on the end of the optical fiber [20]. Fig.…”

Current state of the research on optoacoustic fiber-optic ultrasonic transducers based on thermoelastic effect and fiber-optic interferometric receivers

“…10a shows layout of thermophysical simulation of surface nanostructures for optoacoustic fiber-optic transducers. As it was shown previously, surface nanostructure is characterized by very high aspect ratio [160]. Therefore, uniform temperature distribution boundaries can be used at some distance from the monolayer of NPs.…”

“…This, based on the linearity of the interaction of optical radiation with the nanostructure, makes it possible to use the principle of superposition, since in the nanostructure in the form of a monolayer of nanoparticles on the surface of a solid body, there are a sufficient number of regions in which there is a quasi-periodic arrangement of nanoparticles. Moreover, in nanostructures in the form of a monolayer of nanoparticles on the surface of a solid body, collective interactions take place in the system "ensemble of nanoparticles-substrate-environment", which allows us to speak about the formation of a "collective" electromagnetic field [160,161]. The superposition of the responses of an ensemble of such regions forms the response of the entire nanostructure in practice.…”

“…Then, set the boundary conditions should be chosen. Optoacoustic transducer consisting of monolayer of monodisperse metal NPs on a substrate (optical fiber edge) has been simulted with the CST Microwave Studio SE [160,163]. Surface nanostructure simulation is realized using the unit cell boundary conditions (translation is carried out in two dimensions to infinity).…”

Thermophysical and mechanical properties of active membranes for photoacoustic generators of forced acoustic oscillations

“…The frequency bandwidth greater than 5 MHz is achieved in the studied case at an offset amplitude over 35−40 µm. For a heat release power of 40 mW it is characteristic for the studied structure that maximum increase in temperature does not exceed 100 K, which ensures long-term functioning due to properties of the material used [9,15]. In the area on non-linear oscillations mechanical return forces arise in the membrane that make it bowing in the direction opposite to the initial deformation.…”