Coherent’s patented THz-Raman® Spectroscopy Systems combine chemical detection and structural analysis in one instrument. These systems are saving time and money; improving forensic and scientific analysis; and delivering faster, more reliable results across a wide variety of applications.
Raman spectroscopy has rapidly gained acceptance as an invaluable tool for detecting, quantifying, and analyzing the chemical composition of materials across a broad range of industries, enabling faster, easier, less expensive, more compact, and even portable spectral analysis for an ever-broadening list of applications. However many material characterization tasks require the analysis of the molecular structure of a substance as well as deciphering its chemical constituents and concentrations. Molecular structure is important because molecules can exist in different or “polymorphic” forms that can significantly impact their chemical, optical, electromechanical, and/or biological properties. Additionally, molecular structure can be indicative of formulation/synthesis methods, storage and environmental exposures (heat, moisture), and contaminants.
Today, structural chemistry is principally the domain of x-ray diffraction (XRD), Fourier transform infrared (FTIR), and terahertz (THz) absorption spectroscopy. Unfortunately, these techniques can be destructive, expensive, and/or require large sample sizes and preparation, and in some cases are further limited by physical form of the sample (gas, liquid, or solid) or experimental conditions (such as the presence of moisture or air). Coherent’s patented VHG-based THz-Raman® systems extend Raman into the terahertz/low frequency/low wavenumber regime, delivering both chemical identification and structural analysis in a simplified, one-measurement solution.
As with all Raman systems, THz-Raman® spectroscopy is inherently nondestructive, non-invasive, works with trace amounts of any substance in nearly any lab or field environment, and requires no sample preparation. However, THz-Raman systems cover both anti-Stokes and Stokes shifts from <-3000cm-1 to > 3000cm-1 (depending on spectrometer range), while only blocking the Rayleigh excitation frequency to within about +/- 5 cm-1 . This allows probing of low-energy vibrations in terahertz frequencies (also known as low frequency, or low wavenumber regions), which correlate to molecular structure.
The various spectral regions are shown schematically:
Please Read Before Continuing
Risk factors: Except for the historical information contained here, many of the matters discussed in this Web site are forward-looking statements, based on expectations at the time they were made, that involve risks and uncertainties that could cause our results to differ materially from those expressed or implied by such statements. These risks are detailed in the “Factors That May Affect Future Results” section of our latest 10-K or 10-Q filing. Coherent assumes no obligation to update these forward-looking statements.