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Optics Express Jun 2015We present a helix photonic metamaterial that exhibits nondispersive optical rotation in a broad passband at optical frequencies. Several features, including zero...
We present a helix photonic metamaterial that exhibits nondispersive optical rotation in a broad passband at optical frequencies. Several features, including zero dispersion, zero ellipticity, and high transmission, can be simultaneously achieved in the presented structure. Pure optical rotation with extremely low dispersion is exhibited in a broad band covering the optical telecommunication wavelengths along with high transmission above 95%. We show that the chiral responses as well as the wavelength-dependent properties of the passband are governed by the behaviors of adjacent resonances. A systematic study of the optical properties with various geometrical parameters is performed, where the dependence of passband properties on resonance behaviors is examined and discussed. Such broadband dispersion-free optical rotation at optical frequencies may be of great interest for high-performance polarization manipulation and relevant applications.
PubMed: 26191689
DOI: 10.1364/OE.23.016772 -
Sensors (Basel, Switzerland) Feb 2021A chiral sensor with optical rotation detection based on weak measurement for the kinetic study of sucrose hydrolysis is presented. Based on the polarization modulation...
A chiral sensor with optical rotation detection based on weak measurement for the kinetic study of sucrose hydrolysis is presented. Based on the polarization modulation to the pre-selection state, the optical rotation of chiral sample was accurately determined through the central wavelength shift of the output spectrum. With this approach, the concentration response curves of sucrose and its hydrolysis products, i.e., fructose and glucose, were experimentally obtained for the hydrolysis analysis. By collecting the output spectrum with a frequency of 100 Hz and fitting the central wavelength shift synchronously during the measurement, the sucrose hydrolysis process was monitored in real time. Different hydrolysis conditions with varied concentration of invertase enzyme and citrate were implemented in this work. As a consequence, the real-time hydrolysis curves of the hydrolysis process with distinct velocities was achieved and analyzed. Such a kinetic monitoring about sucrose hydrolysis with optical rotation detection technology played a critical role in the researches involving sucrose, and also revealed the great potential of weak measurement in intersections, such as food safety inspection and chemical analysis.
PubMed: 33540721
DOI: 10.3390/s21031003 -
Spectrochimica Acta. Part A, Molecular... Nov 2023Following its first observation 50 years ago Raman optical activity (ROA), which refers to a circular polarization dependence of Raman scattering from chiral molecules,... (Review)
Review
Following its first observation 50 years ago Raman optical activity (ROA), which refers to a circular polarization dependence of Raman scattering from chiral molecules, has evolved into a powerful chiroptical spectroscopy for studying a large range of biomolecules in aqueous solution. Among other things ROA provides information about motif and fold as well as secondary structure of proteins; structure of carbohydrates and nucleic acids; polypeptide and carbohydrate structure of intact glycoproteins; and protein and nucleic acid structure of intact viruses. Quantum chemical simulations of observed Raman optical activity spectra can provide complete three-dimensional structures of biomolecules, together with information about conformational dynamics. This article reviews how ROA has provided new insight into the structure of unfolded/disordered states and sequences, ranging from the complete disorder of the random coil to the more controlled type of disorder exemplified by poly L-proline II helix in proteins, high mannose glycan chains in glycoproteins and constrained dynamic states of nucleic acids. Possible roles for this 'careful disorderliness' in biomolecular function, misfunction and disease are discussed, especially amyloid fibril formation.
Topics: Optical Rotation; Peptides; Glycoproteins; Protein Structure, Secondary; Spectrum Analysis, Raman; Nucleic Acids
PubMed: 37269652
DOI: 10.1016/j.saa.2023.122959 -
Optics Express Mar 2015Measuring optical rotations in materials is a useful tool in many experimental studies. Research may be limited by the ability to measure small rotations due to weak...
Measuring optical rotations in materials is a useful tool in many experimental studies. Research may be limited by the ability to measure small rotations due to weak interactions. We propose a novel scheme wherein we use a coupled waveguide and ring resonator to amplify the effects of optical rotation, potentially opening new avenues for investigation. Our proposed device can increase the resulting optical rotation by up to six orders of magnitude.
PubMed: 25836829
DOI: 10.1364/OE.23.006050 -
Optics Express Nov 2020This paper investigates the laser polarization error in the optical rotation detection system (ORDS) of an atomic comagnetometer (ACM), which will seriously degrade the...
This paper investigates the laser polarization error in the optical rotation detection system (ORDS) of an atomic comagnetometer (ACM), which will seriously degrade the long-term performance of the ORDS. We first establish an optical transmission model of the ORDS by using Jones matrix concerning the optical imperfection of polarizers. Then, we analyze the polarization error based on this model and propose a novel error suppression method. Finally, we experimentally test the long-term performance of the ORDS and the ACM before and after the polarization error suppression to verify the effectiveness of the proposed method. The experimental results show that the long-term performance of the ORDS and the ACM can be improved by approximately 3.4 times with the proposed polarization error suppression method.
PubMed: 33379685
DOI: 10.1364/OE.406073 -
Scientific Reports Mar 2021Laguerre-Gaussian (LG) beams contain a helical phase front with a doughnut-like intensity profile. We use the LG beam to introduce a rather simple method for generation...
Laguerre-Gaussian (LG) beams contain a helical phase front with a doughnut-like intensity profile. We use the LG beam to introduce a rather simple method for generation of a vector beam (VB), a beam with spatially-dependent polarization in the beam cross section, via the nonlinear magneto-optical rotation (NMOR). We consider the NMOR of the polarization of a linearly polarized probe field passing through an inverted Y-type four-level quantum system interacting with a LG control field and a static magnetic field. It is shown that the polarization of the transmitted field is spatially distributed by the orbital angular momentum (OAM) of the LG control field, leading to generation of the VB with azimuthally symmetric polarization distribution. We show that the polarization and intensity distributions of the VB spatially vary by changing the OAMs of the LG control field. Moreover, the radial index of the LG control field has a major role in more spatially polarization distributing of the VB. It is shown that the intensity of the generated VBs in different points of the beam cross section can be controlled by the OAM as well as the radial index of the LG control field. However, the VB with highly spatially distributed can be generated for higher values of the radial index of LG control field. The analytical calculations determine the contribution of the different nonlinear (cross-Kerr effect) phenomena on the generation of the VB. We show that the VB is mainly generated via birefringence induced by the applied fields. Finally, we use asymmetric LG (aLG) beams for making the VBs with asymmetric polarization distribution. It is shown that by applying aLG beams, the azimuthal symmetry of the polarization distribution breaks and the asymmetric polarization distribution can be controlled by OAM and radial index of the aLG control field. The obtained results may find more interesting applications in fiber/free space optical communication to enhance the capacity of the information transmission.
PubMed: 33727617
DOI: 10.1038/s41598-021-85249-8 -
Self-referenced, microdegree, optical rotation polarimeter for biomedical applications: an analysis.Journal of Biomedical Optics Jul 2016We comprehensively analyze the performance of a type of optical rotation (OR) polarimeter, which has been designed from the outset to fit the special requirements of two...
We comprehensively analyze the performance of a type of optical rotation (OR) polarimeter, which has been designed from the outset to fit the special requirements of two major applications: general chiral detection during the separation of optical isomers by high-pressure liquid chromatography systems in the pharmaceutical industry, and monitoring of glucose in the interstitial fluid of diabetics by a fully implanted long-term optical sensor. Both very demanding applications call for an OR polarimeter that can be miniaturized while maintaining high resolution and accuracy in the microdegree range in the face of considerable noise from various sources. These two characteristics—miniature size and immunity to noise—set this polarimeter apart from the traditional OR polarimeters currently in use, which are both bulky and very susceptible to noise. The following detailed analysis demonstrates the advantages of this polarimeter and its potential as an analytic and diagnostic tool.
Topics: Equipment Design; Glucose; Linear Models; Optical Rotation; Optics and Photonics
PubMed: 26720051
DOI: 10.1117/1.JBO.21.7.071104 -
Journal of Chemical Education Aug 2020An easily constructed and inexpensive polarimeter with an optical rotation angle resolution of about 0.5° is presented. It is made from small pieces of polarizing film,...
An easily constructed and inexpensive polarimeter with an optical rotation angle resolution of about 0.5° is presented. It is made from small pieces of polarizing film, 2 LEDs, a protractor, and a few wires, all held in place with plastic interlocking toy bricks, such as Lego bricks. The instrument was used to demonstrate the optical rotation of plane polarized light as a function of concentration, path length, temperature, and wavelength, and to determine enantiomeric excess in solutions of arabinose, the amount of limonene in citrus ski wax remover, and optical rotations of various types of honeys and essential oils. Results were comparable to values obtained on a commercial scientific instrument, and with literature values.
PubMed: 32905174
DOI: 10.1021/acs.jchemed.9b00763 -
Scientific Reports Jul 2016We present an experimental and computational study of the response of twisted-cross metamaterials that provide near dispersionless optical rotation across a broad band...
We present an experimental and computational study of the response of twisted-cross metamaterials that provide near dispersionless optical rotation across a broad band of frequencies from 19 GHz to 37 GHz. We compare two distinct geometries: firstly, a bilayer structure comprised of arrays of metallic crosses where the crosses in the second layer are twisted about the layer normal; and secondly where the second layer is replaced by the complementary to the original, i.e. an array of cross-shaped holes. Through numerical modelling we determine the origin of rotatory effects in these two structures. In both, pure optical rotation occurs in a frequency band between two transmission minima, where alignment of electric and magnetic dipole moments occurs. In the cross/cross metamaterial, the transmission minima occur at the symmetric and antisymmetric resonances of the coupled crosses. By contrast, in the cross/complementary-cross structure the transmission minima are associated with the dipole and quadrupole modes of the cross, the frequencies of which appear intrinsic to the cross layer alone. Hence the bandwidth of optical rotation is found to be relatively independent of layer separation.
PubMed: 27457405
DOI: 10.1038/srep30307 -
Fluorescence and Optical Activity of Chiral CdTe Quantum Dots in Their Interaction with Amino Acids.ACS Nano Apr 2020Ligand-induced chirality in semiconducting nanocrystals has been the subject of extensive study in the past few years and shows potential applications in optics and...
Ligand-induced chirality in semiconducting nanocrystals has been the subject of extensive study in the past few years and shows potential applications in optics and biology. Yet, the origin of the chiroptical effect in semiconductor nanoparticles is still not fully understood. Here, we examine the effect of the interaction with amino acids on both the fluorescence and the optical activity of chiral semiconductor quantum dots (QDs). A significant fluorescence enhancement is observed for l/d-Cys-CdTe QDs upon interaction with all the tested amino acids, indicating suppression of nonradiative pathways as well as the passivation of surface trap sites brought the interaction of the amino group with the CdTe QDs' surface. Heterochiral amino acids are shown to weaken the circular dichroism (CD) signal, which may be attributed to a different binding configuration of cysteine molecules on the QDs' surface. Furthermore, a red shift of both CD and fluorescence signals in l/d-Cys-CdTe QDs is only observed upon adding cysteine, while other tested amino acids do not exhibit such an effect. We speculate that the thiol group induces orbital hybridization of the highest occupied molecular orbital (HOMOs) of cysteine and the valence band of CdTe QDs, leading to the decrease of the energy band gap and a concomitant red shift of CD and fluorescence spectra. This is further verified by density functional theory calculations. Both the experimental and theoretical findings indicate that the addition of ligands that do not "directly" interact with the valence band (VB) of the QD (noncysteine moieties) changes the QD photophysical properties, as it probably modifies the way cysteine is bound to the surface. Hence, we conclude that it is not only the chemistry of the amino acid ligand that affects both CD and PL but also the exact geometry of binding that modifies these properties. Understanding the relationship between the QD's surface and chiral amino acid thus provides an additional perspective on the fundamental origin of induced chiroptical effects in semiconductor nanoparticles, potentially enabling us to optimize the design of chiral semiconductor QDs for chiroptic applications.
Topics: Amino Acids; Cadmium Compounds; Optical Rotation; Quantum Dots; Tellurium
PubMed: 32298573
DOI: 10.1021/acsnano.9b09101