Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Open hardware microsecond dispersive transient absorption spectrometer for linear optical response.

ABSTRACT: An open hardware design and implementation for a transient absorption spectrometer are presented that has microsecond time resolution and measures full difference spectra in the visible spectral region from 380 to 750 nm. The instrument has been designed to allow transient absorption spectroscopy measurements of either low or high quantum yield processes by combining intense sub-microsecond excitation flashes using a xenon lamp together with stroboscopic non-actinic white light probing using LED sources driven under high pulsed current from a capacitor bank. The instrument is sensitive to resolve 0.15 mOD flash-induced differences within 1000 measurements at 20 Hz repetition rate using an inexpensive CCD sensor with 200 μm pixel dimension, 40 K electrons full well capacity and a dynamic range of 1800. The excitation flash has 230 ns pulse duration and the 2 mJ flash energy allows spectral filtering while retaining high power density with focussing to generate mOD signals in the 10^-4-10^-1 ΔOD range. We present the full electronics design and construction of the flash and probe sources, the optics as well as the timing electronics and CCD spectrometer operation and modification for internal signal referencing. The performance characterisation and example measurements are demonstrated using microsecond TAS of Congo red dye, as an example of a low quantum yield photoreaction at 2% with up to 78% of molecules excited. The instrument is fully open hardware and combines inexpensive selection of commercial components, optics and electronics and allows linear response measurements of photoinduced reactions for the purpose of accurate global analysis of chemical dynamics.

SUBMITTER: Hutchison CDM

PROVIDER: S-EPMC8799588 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Broadband THz absorption spectrometer based on excitonic nonlinear optical effects.

Project description:A broadly tunable THz source is realized via difference frequency generation, in which an enhancement to χ(3) that is obtained via resonant excitation of III-V semiconductor quantum well excitons is utilized. The symmetry of the quantum wells (QWs) is broken by utilizing the built-in electric-field across a p-i-n junction to produce effective χ(2) processes, which are derived from the high χ(3). This χ(2) media exhibits an onset of nonlinear processes at ~4 W cm-2, thereby enabling area (and, hence, power) scaling of the THz emitter. Phase matching is realized laterally through normal incidence excitation. Using two collimated 130 mW continuous wave (CW) semiconductor lasers with ~1-mm beam diameters, we realize monochromatic THz emission that is tunable from 0.75 to 3 THz and demonstrate the possibility that this may span 0.2-6 THz with linewidths of ~20 GHz and efficiencies of ~1 × 10-5, thereby realizing ~800 nW of THz power. Then, transmission spectroscopy of atmospheric features is demonstrated, thereby opening the way for compact, low-cost, swept-wavelength THz spectroscopy.

| S-EPMC6414654 | biostudies-literature

OPTiM: Optical projection tomography integrated microscope using open-source hardware and software.

Project description:We describe the implementation of an OPT plate to perform optical projection tomography (OPT) on a commercial wide-field inverted microscope, using our open-source hardware and software. The OPT plate includes a tilt adjustment for alignment and a stepper motor for sample rotation as required by standard projection tomography. Depending on magnification requirements, three methods of performing OPT are detailed using this adaptor plate: a conventional direct OPT method requiring only the addition of a limiting aperture behind the objective lens; an external optical-relay method allowing conventional OPT to be performed at magnifications >4x; a remote focal scanning and region-of-interest method for improved spatial resolution OPT (up to ~1.6 μm). All three methods use the microscope's existing incoherent light source (i.e. arc-lamp) and all of its inherent functionality is maintained for day-to-day use. OPT acquisitions are performed on in vivo zebrafish embryos to demonstrate the implementations' viability.

| S-EPMC5507440 | biostudies-literature

A multi-crystal wavelength dispersive x-ray spectrometer.

Project description:A multi-crystal wavelength dispersive hard x-ray spectrometer with high-energy resolution and large solid angle collection is described. The instrument is specifically designed for time-resolved applications of x-ray emission spectroscopy (XES) and x-ray Raman scattering (XRS) at X-ray Free Electron Lasers (XFEL) and synchrotron radiation facilities. It also simplifies resonant inelastic x-ray scattering (RIXS) studies of the whole 2d RIXS plane. The spectrometer is based on the Von Hamos geometry. This dispersive setup enables an XES or XRS spectrum to be measured in a single-shot mode, overcoming the scanning needs of the Rowland circle spectrometers. In conjunction with the XFEL temporal profile and high-flux, it is a powerful tool for studying the dynamics of time-dependent systems. Photo-induced processes and fast catalytic reaction kinetics, ranging from femtoseconds to milliseconds, will be resolvable in a wide array of systems circumventing radiation damage.

| S-EPMC3422323 | biostudies-other

Charge Dynamics of a CuO Thin Film on Picosecond to Microsecond Timescales Revealed by Transient Absorption Spectroscopy.

Project description:Understanding the mechanism of charge dynamics in photocatalysts is the key to design and optimize more efficient materials for renewable energy applications. In this study, the charge dynamics of a CuO thin film are unraveled via transient absorption spectroscopy (TAS) on the picosecond to microsecond timescale for three different excitation energies, i.e., above, near, and below the band gap, to explore the role of incoherent broadband light sources. The shape of the ps-TAS spectra changes with the delay time, while that of the ns-TAS spectra is invariant for all the excitation energies. Regardless of the excitations, three time constants, τ1 ∼ 0.34-0.59 ps, τ2 ∼ 162-175 ns, and τ3 ∼ 2.5-3.3 μs, are resolved, indicating the dominating charge dynamics at very different timescales. Based on these observations, the UV-vis absorption spectrum, and previous findings in the literature, a compelling transition energy diagram is proposed. Two conduction bands and two defect (deep and shallow) states dominate the initial photo-induced electron transitions, and a sub-valence band energy state is involved in the subsequent transient absorption. By solving the rate equations for the pump-induced population dynamics and implementing the assumed Lorentzian absorption spectral shape between two energy states, the TAS spectra are modeled which capture the main spectral and time-dependent features for t > 1 ps. By further considering the contributions from free-electron absorption during very early delay times, the modeled spectra reproduce the experimental spectra very well over the entire time range and under different excitation conditions.

| S-EPMC10103062 | biostudies-literature

High-speed device synchronization in optical microscopy with an open-source hardware control platform.

Project description:Azimuthal beam scanning eliminates the uneven excitation field arising from laser interference in through-objective total internal reflection fluorescence (TIRF) microscopy. The same principle can be applied to scanning angle interference microscopy (SAIM), where precision control of the scanned laser beam presents unique technical challenges for the builders of custom azimuthal scanning microscopes. Accurate synchronization between the instrument computer, beam scanning system and excitation source is required to collect high quality data and minimize sample damage in SAIM acquisitions. Drawing inspiration from open-source prototyping systems, like the Arduino microcontroller boards, we developed a new instrument control platform to be affordable, easily programmed, and broadly useful, but with integrated, precision analog circuitry and optimized firmware routines tailored to advanced microscopy. We show how the integration of waveform generation, multiplexed analog outputs, and native hardware triggers into a single central hub provides a versatile platform for performing fast circle-scanning acquisitions, including azimuthal scanning SAIM and multiangle TIRF. We also demonstrate how the low communication latency of our hardware platform can reduce image intensity and reconstruction artifacts arising from synchronization errors produced by software control. Our complete platform, including hardware design, firmware, API, and software, is available online for community-based development and collaboration.

| S-EPMC6704125 | biostudies-literature

Resonant inelastic X-ray scattering using a miniature dispersive Rowland refocusing spectrometer.

Project description:X-ray absorption spectroscopy (XAS) beamlines worldwide are steadily increasing their emphasis on full photon-in/photon-out spectroscopies, such as resonant inelastic X-ray scattering (RIXS), resonant X-ray emission spectroscopy (RXES) and high energy resolution fluorescence detection XAS (HERFD-XAS). In such cases, each beamline must match the choice of emission spectrometer to the scientific mission of its users. Previous work has recently reported a miniature tender X-ray spectrometer using a dispersive Rowland refocusing (DRR) geometry that functions with high energy resolution even with a large X-ray spot size on the sample [Holden et al. (2017). Rev. Sci. Instrum. 88, 073904]. This instrument has been used in the laboratory in multiple studies of non-resonant X-ray emission spectroscopy using a conventional X-ray tube, though only for preliminary measurements at a low-intensity microfocus synchrotron beamline. This paper reports an extensive study of the performance of a miniature DRR spectrometer at an unfocused wiggler beamline, where the incident monochromatic flux allows for resonant studies which are impossible in the laboratory. The results support the broader use of the present design and also suggest that the DRR method with an unfocused beam could have important applications for materials with low radiation damage thresholds and that would not survive analysis on focused beamlines.

| S-EPMC7064111 | biostudies-literature

Open Hardware in Science: The Benefits of Open Electronics.

Project description:Openly shared low-cost electronic hardware applications, known as open electronics, have sparked a new open-source movement, with much untapped potential to advance scientific research. Initially designed to appeal to electronic hobbyists, open electronics have formed a global "maker" community and are increasingly used in science and industry. In this perspective article, we review the current costs and benefits of open electronics for use in scientific research ranging from the experimental to the theoretical sciences. We discuss how user-made electronic applications can help (I) individual researchers, by increasing the customization, efficiency, and scalability of experiments, while improving data quantity and quality; (II) scientific institutions, by improving access to customizable high-end technologies, sustainability, visibility, and interdisciplinary collaboration potential; and (III) the scientific community, by improving transparency and reproducibility, helping decouple research capacity from funding, increasing innovation, and improving collaboration potential among researchers and the public. We further discuss how current barriers like poor awareness, knowledge access, and time investments can be resolved by increased documentation and collaboration, and provide guidelines for academics to enter this emerging field. We highlight that open electronics are a promising and powerful tool to help scientific research to become more innovative and reproducible and offer a key practical solution to improve democratic access to science.

| S-EPMC9617215 | biostudies-literature

Polarization-dispersive imaging spectrometer for scattering circular dichroism spectroscopy of single chiral nanostructures.

Project description:Circular dichroism spectroscopy is one of the most important tools in nanoscopic chiroptics. However, there is lack of simple, fast and reliable method for measuring the circular dichroism responses of single nanostructures. To tackle this issue, we report a polarization-dispersive imaging spectrometer which is capable of measuring the scattering circular dichroism response of a single chiral nanostructure with a single shot. Using this technique, we studied the scattering circular dichroism spectra of a model system, the vertically coupled plasmonic nanorod pair. Both experimental and theoretical results indicate that the polarization-dispersive spectrometer measures the imaginary part of nonlocal susceptibility of the structure. We further applied the technique to 3-dimensional Au nanorod structures assembled on DNA origami templates together with correlated scanning electron microscopic measurements. Rich chiroptical phenomena were unveiled at the single nanostructure level.

| S-EPMC8933428 | biostudies-literature

Optical inter-site spin transfer probed by energy and spin-resolved transient absorption spectroscopy.

Project description:Optically driven spin transport is the fastest and most efficient process to manipulate macroscopic magnetization as it does not rely on secondary mechanisms to dissipate angular momentum. In the present work, we show that such an optical inter-site spin transfer (OISTR) from Pt to Co emerges as a dominant mechanism governing the ultrafast magnetization dynamics of a CoPt alloy. To demonstrate this, we perform a joint theoretical and experimental investigation to determine the transient changes of the helicity dependent absorption in the extreme ultraviolet spectral range. We show that the helicity dependent absorption is directly related to changes of the transient spin-split density of states, allowing us to link the origin of OISTR to the available minority states above the Fermi level. This makes OISTR a general phenomenon in optical manipulation of multi-component magnetic systems.

| S-EPMC7018696 | biostudies-literature

Numerical study of transient absorption saturation in single-layer graphene for optical nanoscopy applications.

Project description:Transient absorption, or pump-probe microscopy is an absorption-based technique that can explore samples ultrafast dynamic properties and provide fluorescence-free contrast mechanisms. When applied to graphene and its derivatives, this technique exploits the graphene transient response caused by the ultrafast interband transition as the imaging contrast mechanism. The saturation of this transition is fundamental to allow for super-resolution optical far-field imaging, following the reversible saturable optical fluorescence transitions (RESOLFT) concept, although not involving fluorescence. With this aim, we propose a model to numerically compute the temporal evolution under saturation conditions of the single-layer graphene molecular states, which are involved in the transient absorption. Exploiting an algorithm based on the fourth order Runge-Kutta (RK4) method, and the density matrix approach, we numerically demonstrate that the transient absorption signal of single-layer graphene varies linearly as a function of excitation intensity until it reaches saturation. We experimentally verify this model using a custom pump-probe super-resolution microscope. The results define the intensities necessary to achieve super-resolution in a pump-probe nanoscope while studying graphene-based materials and open the possibility of predicting such a saturation process in other light-matter interactions that undergo the same transition.

| S-EPMC11350070 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data