Browsing Department of Chemistry Faculty Publications by Title
Now showing items 33-52 of 78
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An Improved Route for the Synthesis of Guanine Quadruplex Ligand
(Thieme Stuttgart-New York, 2018-04-24)The recognition of non-canonical DNA and RNA architectures such as guanine quadruplexes by small molecule ligands has become a promising strategy for anticancer and antiviral applications in recent years, leading to an ... -
Instantaneous photoinduced patterning of an azopolymer colloidal nanosphere assembly
(OSA, 2016-09-01)Colloidal azopolymer nanospheres assembled on a glass substrate were exposed to a single collimated laser beam. The combination of photo-fluidic elongation of the spherical colloids and light induced self-organization of ... -
An Intertwined Method for Making Low-Rank, Sum-Of-Product Basis Functions that makes it Possible to Compute Vibrational Spectra of Molecules with more than 10 Atoms
(2017-05-31)We propose a method for solving the vibrational Schrödinger equation with which one can compute spectra for molecules with more than ten atoms. It uses sum-of-product (SOP) basis functions stored in a canonical polyadic ... -
Iterative Methods for Computing Vibrational Spectra
(2017-12-21)I review some computational methods for calculating vibrational spectra. They all use iterative eigensolvers to compute eigenvalues of a Hamiltonian matrix by evaluating matrix-vector products. A direct-product basis can ... -
Long-Period Gratings in Chemical Sensing
(2016-03-21)A chemical sensor system consisting of a coated long period grating, which was spliced into a fiber loop cavity, has been prepared and characterized. Designer coatings based on polydimethylsiloxane and nanostructured ... -
Loss Determination in Microsphere Resonators by Phase-Shift Cavity Ring-Down Measurements
(2016-03-21)The optical loss of whispering gallery modes of resonantly excited microresonator spheres is determined by optical lifetime measurements. The phase-shift cavity ring-down technique is used to extract ring-down times and ... -
Measurements of Energy Partitioning in H2 Formation by Photolysis of Amorphous Water Ice
(2016-03-21)We demonstrate experimentally that photodissociation of amorphous solid water at 100 K results in formation of H2 molecules with an ortho/para ratio of gOPR = 3. Two distinct mechanisms can be identified: endothermic ... -
Modeling of Fiber-Optic Fluorescence Probes for Strongly Absorbing Samples
(2016-03-08)The dynamic range of fiber-optic fluorescent probes such as single fibers and fiber bundles is calculated for strongly absorbing samples, such as process liquids, foodstuffs, and lubricants. The model assumes an excitation ... -
Monitoring of Vapor Uptake by Refractive Index and Thickness Measurements in Thin Films
(2016-03-04)We report a method for real-time monitoring of vapor uptake by simultaneous detection of the refractive index, 𝑛 , and thickness, 𝑑 , of thin transparent films with a precision of 𝛿𝑛=10 −4 and 𝛿𝑑<100 nm . The setup ... -
A Multi-Dimensional Smolyak Collocation Method in Curvilinear Coordinates for Computing Vibrational Spectra
(2015-12-02)In this paper, we improve the collocation method for computing vibrational spectra that was presented in Avila and Carrington, Jr. [J. Chem. Phys. 139, 134114 (2013)]. Using an iterative eigensolver, energy levels and ... -
Musical Instrument Pickup Based on a Laser Locked to an Optical Fiber Resonator
(2016-03-11)A low-noise transducer based on a fiber Fabry-Perot (FFP) cavity was used as a pickup for an acoustic guitar. A distributed feedback (DFB) laser was locked to a 25 MHz-wide resonance of the FFP cavity using the Pound-Drever-Hall ... -
Musical Instrument Recordings Made With a Fiber Fabry–Perot Cavity: Photonic Guitar Pickup
(2016-03-17)A 1 cm long, low-finesse fiber-optic cavity was used as a transducer for the vibrations of the soundboard of an acoustic guitar and of a violin. The reflected light is detected and then amplified and recorded using ... -
Near Infrared Absorption Detection in Picolitre Liquid Volumes Using Fiber Loop Ring-Down Detection
(2016-03-07)Cavity ring-down spectroscopy is performed using a single-mode fibre loop as an optical cavity. The loop contains absorption cells for either liquids or gases, as well as an erbium-doped fibre amplifier. The fibre amplifier ... -
Neural Networks vs Gaussian Process Regression for Representing Potential Energy Surfaces: a Comparative Study of Fit Quality and Vibrational Spectrum Accuracy
(2018)For molecules with more than three atoms, it is difficult to fit or interpolate a potential energy surface (PES) from a small number of (usually ab initio) energies at points. Many methods have been proposed in recent ... -
A New Collocation-Based Multi-Configuration Time-Dependent Hartree (MCTDH) Approach for Solving the Schrödinger Equation With a General Potential Energy Surface
(2018-01-08)We present a new collocation-based multi-configuration time-dependent Hartree (MCTDH) approach for solving the Schrödinger equation required to compute (ro-)vibrational spectra, photodissociation cross sections, reaction ... -
Optical Fiber Sensing Based on Reflection Laser Spectroscopy
(2016-03-22)An overview on high-resolution and fast interrogation of optical-fiber sensors relying on laser reflection spectroscopy is given. Fiber Bragg-gratings (FBGs) and FBG resonators built in fibers of different types are used ... -
Perspective: Computing (ro-)Vibrational Spectra of Molecules With More Than Four Atoms
(2017-03-31)In this perspective, I review methods for computing (ro-)vibrational energy levels and wavefunctions of molecules with more than four atoms. I identify three problems one confronts (1) reducing the size of the basis; (2) ... -
Phase-Shift Cavity Ring-Down Spectroscopy on a Microsphere Resonator by Rayleigh Backscattering
(2016-03-04)The optical ring-down time in a silica microsphere resonator is measured using phase-shift cavity ring-down spectroscopy. When detecting Rayleigh backscattered light that is coupled into the input waveguide it is found ... -
Photoelectron Imaging Following 2 þ 1 Multiphoton Excitation of HBr
(2016-03-29)The photodissociation and photoionization dynamics of HBr via low-n Rydberg and ion-pair states was studied by using 2 + 1 REMPI spectroscopy and velocity map imaging of photoelectrons. Two-photon excitation at about 9.4–10 ... -
Photonic Guitar Pick-up: Fiber Strain Sensors Find Applications in Music Recording
(2016-03-07)In this report we give a summary of our work on the development of low-noise fiber-optic strain sensors. Three types of strain sensors were developed and were tested by attaching them to the bodies of acoustic guitars. The ...