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A. Karabchevsky

Publications and source records attributed to A. Karabchevsky.

2 recordsLinked to original sources

Green-Graphene protective overlayer on optical microfibers: pro-longs the device lifetime

Optical microfibers finds new applications in various fields of industry, which in turn requires wear resistance, environmental friendliness and ease of use. However, optical microfibers are fragile. Here we report a new method to prolong the microfiber lifetime by modifying its surface with green-extracted graphene overlayers. Graphene films were obtained by dispergation of shungite mineral samples in an aqueous medium. For this, we tapered optical fibers and sculptured them with graphene films mixed with gold nanoparticles. We observed that due to the surface modification the lifetime and survivability of the microfiber increased 5 times, as compared to the bare microfiber. The embedded gold nanoparticles can also be utilized for enhanced sensitivity and other applications.

physics.app-ph

High-Q surface electromagnetic wave resonance excitation in magneto-photonic crystals for super-sensitive detection of weak light absorption in near-IR

Mid-infrared spectrum can be recorded from almost any material making the mid-infrared spectroscopy an extremely important and widely used sample characterization and analytical technique. However, sensitivity photoconductive detectors operate primarily in the near-infrared (NIR) but not in the mid-infrared making the NIR more favorable for accurate spectral analysis. Although absorption cross-section of vibrational modes in near-infrared is orders of magnitude smaller compared to the fundamental vibrations in mid-infrared, different concepts were proposed to increase the detectability of weak molecular transitions overtones. Yet, the contribution of magneto-photonic structures in near-infrared absorption effect has never been explored so far. Here we propose high-Q magneto-photonic structures for a super-sensitive detection of weak absorption resonances in near-infrared. We analyze the contributions of both magnetic and non-magnetic photonic crystal (PC) configurations to the detection of weak molecular transitions overtones. Our results constitute an important step towards development of highly sensitive spectroscopic tools based on high-Q magneto-photonic sensors.

physics.optics