Interferometric Doppler Raman
Method for Chemical Detection and Imaging
Available for Licensing
US Utility Patent Pending
At A Glance
- The invention is a new method for extremely sensitive chemical detection and imaging using a form of Doppler
- This new method enables orders of magnitude of increased sensitivity using interferometric detection of phase accumulation following the frequency shift acquired in Doppler Raman spectroscopy
- The spectroscopy imaging technique could be used for chemical detection in nearly any industry or application that needs to differentiate molecules, or the chemical nature of compounds
Raman imaging is a powerful technique for generating detailed chemical images based on a sample’s Raman spectrum. A complete spectrum is acquired at each and every pixel of the image, and then interrogated to generate false colour images based on material composition, phase, crystallinity and strain.
In the proposed Interferometric Doppler Raman, a pair of optical probe pulses is used, rather than a single optical probe pulse; more than a pair of optical pulses could be used, however, a pair is the simplest embodiment. The optical probe pulse pair possesses a relative delay (on the order of ps) passes through a Raman active medium after a pump pulse has interacted with the system to excite coherent vibrations in a sample. Either one or both of the probe pulses will arrive after the pump pulse. The interaction of the probe pulses with the vibrationally excited medium will introduce phase and frequency shifts to one or both of the probe pulses. The frequency shift results from a time-varying refractive index that is experienced by the probe pulses (one or both, depending on if one or two pulses follow the pump pulse in time) that imparts a phase modulation on the probe pulses. The pump pulse will be modulated so as to produce a variation in the strength of the excited vibrations in the sample.
- 100,000x more sensitive than existing Raman detection techniques
- Non-invasive chemical detection
Last updated on October 7, 2019.