Photonic Solutions for Chemistry

Absorption Spectroscopy

If light of impinges on an atom or molecule in its ground state, photons of specific energies (wavelengths) are absorbed to promote electrons to an excited state. The absorbed photon energy is determined specifically by the gap between ground and excited state of that particular atom or molecule. Furthermore, by measuring the amount of light absorbed, a quantitative determination of the amount of analyte element present can be made. UV-Vis-NIR spectroscopy is useful to characterise the absorption, transmission, and reflectivity of a variety of materials such as pigments, biological, coatings, windows, filters, or analyse the dynamics of chemical reactions.

Transient Spectroscopy

Transient spectroscopy encompasses a powerful set of techniques for probing and characterizing the electronic and structural properties of short-lived excited states (transient states) of photochemically or photophysically relevant molecules. These states are accessed upon absorption of photons and essentially represent higher energy forms of the molecule, differing from the lowest energy ground state in the distribution of electrons and/or nuclear geometry. 

A battery of complimentary pump-probe techniques is often used in laser spectroscopy laboratories, including Time-Resolved Resonance Raman (TR3) Spectroscopy, Time-Resolved Emission Spectroscopy and Time-Resolved Absorption (Transient Absorption) Spectroscopy.

Micro-Spectroscopy

Micro-Spectroscopy covers a very wide range of spectroscopy modalities with the common character that the spectroscopic measurement is made on the microscopic scale.

Andor spectroscopy systems are routinely used for Raman-based techniques including Micro- Raman and Fluorescence/Photoluminescence, Diffuse Scattering micro-spectroscopy and Multiphoton micro-spectroscopy.

Optical Emission Spectroscopy

OES involves applying an electrical charge to the sample which vaporizing a small amount of material. A discharge plasma with a distinct spectroscopic signature is created, from which the elemental breakdown of the sample can be determined. OES is a rapid method that can be used to determine the elemental composition of a variety of metals and alloys.

OES usually involves collecting highly resolved spectroscopic signature across the Ultra-violet and Visible region of the electromagnetic spectrum.  

X-Ray Spectroscopy

X-ray spectroscopy is an umbrella term for several spectroscopic techniques for characterization of materials by using X-ray excitation, including the likes of X-Ray Absorption (XAS, XANES, EXAFS) and Emission (XES). These modalities are used to probe the electronic structure of atoms or the atomic chemical make-up of a sample. Analysis of the X-ray emission spectrum produces qualitative and quantitative information about the elemental composition of the specimen.

They can provide information on the oxidation state of species, but also find applications for in situ and in operando studies of functional systems (enclosed by opaque structures).

X-Ray Diffraction & Scattering

X-ray diffraction and scattering techniques measure the scattered intensity and/or energy of an X-ray beam to provide detailed information about the crystal structure, chemical composition, and physical properties of materials and thin films. They are non-destructive analytical techniques which are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy. Scattering techniques include Wide-angle X-ray diffraction (WAXD), Small-angle X-ray scattering (SAXS) and Wide-angle X-ray scattering (WAXS). 

Fluorescence Correlation Spectroscopy

Time correlated statistical analysis of fluctuations in fluorescence intensity. This is commonly utilised to provide information on the concentration & size fluctuations of molecules in solution over time. A common application of FCS is the analysis of the concentration fluctuations of fluorescent particles/molecules in solution, in which the fluorescence emitted from a very tiny confocal space in solution is observed. This tiny, focused laser beam waist would typically contain only a small number of fluorescent molecules. Analysis yields the average number of fluorescent particles and average diffusion time when the particle is passing through the probed space, ultimately allowing both concentration and size of the particle to be determined. Such parameters can be important in chemistry and biophysics research.