Fluorescence Anisotropy Sensor Comprising a Dual Hollow-Core Antiresonant Fiber Polarization Beam Splitter

Abstract

Fluorescence anisotropy imaging and sensing is a widely recognized method for studying molecular orientation and mobility. However, introducing this technique to in vivo systems is a challenging task, especially when one considers multiphoton excitation methods. Past two decades have brought a possible solution to this issue in the form of hollow-core antiresonant fibers (HC-ARFs). The continuous development of their fabrication technology has resulted in the appearance of more and more sophisticated structures. One of the most promising concepts concerns dual hollow-core antiresonant fibers (DHC-ARFs), which can be used to split and combine optical signals, effectively working as optical fiber couplers. In this paper, the design of a fluorescence anisotropy sensor based on a DHC-ARF structure is presented. The main purpose of the proposed DHC-ARF is multiphoton-excited fluorescence spectroscopy; however, other applications are also possible.

Fluorescence Anisotropy as a Temperature-Sensing Molecular Probe Using Fluorescein

“…In this present work, we focus on fluorescence anisotropy as an indicator to measure the temperature of a liquid in a microchannel. Other research groups have used fluorescence anisotropy or polarization to evaluate the folding state of proteins [15][16][17]. Fluorescent anisotropy has advantages over LIF, as fluorescence anisotropy is not affected when there is non-uniformity in molecule concentration, incident light intensity, or liquid thickness, because in fluorescence anisotropy, the signal is normalized by the total output light intensity [18].…”

Simple structure dual-core photonic crystal fiber polarization beam splitter covering the O + E + S + C + L + U band based on the surface plasmon resonance effect

“…The PBS plays important roles in the fluorescence anisotropy (FA) measurement, optical coherence tomography (OCT), mode-locked fiber laser, etc. [2][3][4][5]. In the last decade, with the development of the micro/nano fiber fabrication technology, the requirement of all fiber optical systems on the high performance fiber PBS has been continuously increased [6][7][8][9].…”

Towards hollow-core fiber polarization beam splitting and combining

“…In these simulations, the authors calculated the supermodes of the structure and use the formula Lc=π/(βeven-βodd), where βeven and βodd are the lower order even and odd supermode propagation constants, respectively. The coupling polarization dependence is engineered through capillaries with a second glass wall thickness [56,57] or very small air gaps (for all the other designs). Both enhances core-to-cladding coupling that is intrinsically polarization dependent, and which leads to polarization dependence of the coupling between the cores.…”

“…The aim is to know how to design a structure so that it is more resistant to core size difference, that is, for a given core size difference, the decrease in coupling efficiency and length should be smaller. In the literature, the evolution of the coupling coefficient with the geometry for ideal structures has been studied [56][57][58][59][60][61][62][63]. Therefore, the objective is to relate theoretically the coupling length and efficiency between two hollow cores with different radius to the coupling coefficient of the ideal structure (with no core size difference) and the difference of core size.…”