Photonic spin Hall effect enabled refractive index sensor using weak measurements

Abstract

In this work, we theoretically propose an optical biosensor (consists of a BK7 glass, a metal film, and a graphene sheet) based on photonic spin Hall effect (SHE). We establish a quantitative relationship between the spin-dependent shift in photonic SHE and the refractive index of sensing medium. It is found that, by considering the surface plasmon resonance effect, the refractive index variations owing to the adsorption of biomolecules in sensing medium can effectively change the spin-dependent displacements. Remarkably, using the weak measurement method, this tiny spin-dependent shifts can be detected with a desirable accuracy so that the corresponding biomolecules concentration can be determined.

Review of fabrication methods of large-area transparent graphene electrodes for industry

“…Graphene based field-effect-transistor (GFET) sensor is a common and reliable sensor [204], and has been used recently e.g., for early detection of the Zika-virus [205], RNA and DNA detection down to 10 -17 mol/L concentrations [206,207], in operando TEM measurements of neuropeptide capture and release [208] as well as detection of SARS-CoV-2 virus [209], the cause of the global COVID-19 pandemic of 2020. Other measurement schemes can be used as well, such as, Hall effect in standard [210], gated [211] and photonic spin [212,213] Table 2 Summary of different graphene based transparent electrodes, where R s , T, DC / OP and R change refer to sheet resistance, transmittance (at nm unless otherwise specified), figure of merit and decrease of sheet resistance due to doping, respectively. Substrate refers to the substrate where R s and T are measured on, if two substrates are given, then their corresponding measurements are given in brackets after the substrate configurations or optical measurements using e.g., fluorescence [214,215], refractive index imaging [216] or surface plasmons [215,[217][218][219] Terahertz frequency photodetectors are important in many applications, such as, medicine [220], spectroscopy [221] and communications [222].…”

Optics with hyperbolic materials [Invited]

“…In such curved HMM geometry, the splitting of beams for different circular polarizations is enhanced [101]. Photonic spin-Hall effect in HMM enables to manipulate light at nanoscale by means of spin, incident angle, and wavelength, which may lead to potential applications for spin-dependent switching, beam splitters, filters, optical diodes [93], surface sensors [106,107], and quantum information processing [93,94].…”

Pragmatic Implementation With Non-Gaussian Devices of Noise-Limited Weak Value Amplification

“…Weak measurement theory was advanced in 1988 by Aharonov, Albert and Vaidman (AAV) as a way to amplify the pointer shift in quantum measurement systems [1]. Using the weak-value amplification (WVA) effect brought by post-selection, minute changes of physical quantities that are difficult to measure with traditional methods can be measured with unprecedented precision, such as the spin Hall effect of light [2]- [4], ultra-small time-delays [5]- [7] and beam deflections [8]- [10]. In previous studies, the initial wave function of the device is often assumed to be of Gaussian types [11]- [13].…”