THz-Raman® – The “Structural Fingerprint” of Raman
Ondax’s patented1 THz-Raman® Spectroscopy Systems extend the range of traditional Raman spectroscopy into the terahertz/low-frequency regime, exploring the same range of energy transitions as terahertz spectroscopy – without limiting the ability to measure the fingerprint region. This region reveals a new “Structural Fingerprint” to complement the traditional “Chemical Fingerprint” of Raman, enabling simultaneous analysis of both molecular structure and chemical composition in one instrument for advanced materials characterization.
Features
• Robust, sealed optical design with broad operating temperature range for use in demanding environments
• Fiber coupled high power single frequency laser source
• Interchangeable sample interface - probe tip, cuvette holder, tablet holder, or steerable open beam
• Fiber coupled output enables easy interface to a wide range of spectrometers Fast collection of THz-Raman® spectra from 5cm-1 to >3000cm-1 (150GHz to 90THz)
• Simultaneous Stokes and anti-Stokes signals improve SNR while providing inherent calibration reference
• Can be added on to an existing Raman system or spectrometer, or as a complete custom-configured system
• Available at 532nm, 785nm, and 850nm excitation wavelengths
Applications
• Crystallization and Reaction Monitoring
• In-situ Polymorph identification and analysis
• Trace detection and source attribution of explosives/hazmats/drugs
• Structural studies of nano- and bio- materials, photovoltaics, and semiconductors
• Forensics, archeology, mineralogy
See What You’ve Been Missing – More Data, Better Sensitivity & Reliability
Clear real-time differentiation of structural attributes of the material enables clear identification and analysis of polymorphs, raw material sources, defects & contamination, crystal formation, phase monitoring and synthesis methods.
One Sample, One System, One Answer
In-situ, real-time measurement of both composition and structural analysis eliminates the need for multiple samples and instruments, lowering capital, training and maintenance costs.
Benefits
• Both chemical composition + molecular structure from one Raman measurement
• In-situ, real-time structural monitoring + chemical analysis
• Higher SNR with inherent calibration reference
• Faster, more comprehensive and reliable measurements
• Compact, easy to use, and adaptable to existing Raman systems
Full Raman spectrum of the pharmaceutical Carbamazepine showing both the THz-Raman “Structural Fingerprint” and traditional “Chemical Fingerprint” regions. Note higher intensity and symmetry of THz-Raman signals.
Real-time, in-situ monitoring of both structure and composition
THz-Raman® measurements capture low-frequency lattice and phonon modes that are manifested by both inter- and intra-molecular vibrations. These modes are highly responsive to changes in molecular structure and can be used to monitor structural changes caused by polymorphic or isomeric shifts, lattice defects, contaminants, and changes in phase or crystallinity. The example below shows how THz-Raman can be used as a real-time monitor of polymorphic changes in Theophylline.
Reaction Monitoring of Polymorphism
The figure below shows low frequency spectra of anhydrous theophylline (Form II) before and after its transformation into a flocculated slurry (monohydrate, Form M). Spectra collected at the start and finish (T=2s redand T=200s blue) show the disappearance of peaks at 20, 35 and 85 cm-1 in the anhydrate spectrum and the appearance of a new peak at 96 cm-1 in the spectrum of the monohydrate.
The waterfall plot (above right) shows the transformation from Form II to Form
M is complete in approximately 100 seconds. The spectrum of the suspended
solids was resolved from the broad underlying boson peak and the profile
shown above. The time profile shown at right was then generated, which shows
the disappearance of Form II (red) and the appearance of Form M (blue).
Data courtesy Clairet Scientific, Ltd.
Sample Interface Accessories
A variety of sample interface accessories enable the TR-PROBE to be easily configured to match a broad range of applications. Immersion or Contact probe tips may be mounted with either a fixed SwageLok mount or, for longer probes that may need alignmnet, an adjustable tip/tilt probe mount. The Vial/Cuvette Sample Holder incorporates an adjustable steering mirror, interchangeable focusing lens, and safety shutter. And the Steerable Collimated Beam Mount allows for projection and steering of the collimated output beam with precision alignment, for applications requiring long-range collection paths.
THz-Raman® Probe System Specifications:
Parameter
Units
Specification
Wavelength
nm
532
785
850
Power at sample port (min)
mW
25 to 2501
60
60
Physical Dimensions (W x L x H)2
in
3” x 8.5” x 2.3”
3” x 8.5” x 2.3”
3” x 8.5” x 2.3”
1 Specify power level at time of order
2 Probe head only, does not include sample accessory
Spectrometer3:
Fixed Grating Spectrometer
Tunable Grating Spectrometer
Spectral Range (typical)
-200cm-1 to +2200cm-1
400-1100 nm (w/Si Detector)
Spectral Resolution
2.5cm-1 to 4cm-1
0.7 cm-1 or greater
Computer Interface
USB
USB
3 Spectrometer selection and specifications will be determined by application requirements and options ordered
System Description and Configurations:
All THz-Raman® Series platforms are ultra-compact and simple to connect via fiber to almost any spectrometer or Raman system. Our patented SureBlock™ ultra-narrow-band Volume Holographic Grating (VHG) filters precisely block only the Rayleigh excitation with >OD8 attenuation, enabling simultaneous capture of both Stokes and anti-Stokes signals. A high-power, wavelength-stabilized, ASE-free single-frequency laser source is precisely matched to the filters to assure maximum throughput and exceptional attenuation of the excitation source.
The TR-MICRO mounts directly to a broad range of popular microscope platforms and micro-Raman systems, and can be easily switched in and out of the optical path. The system includes an Ondax SureLock™ 785nm, 850nm, or 976nm laser source, notch filters, and optional circular polarization (linear polarization is standard). A 532nm excitation source or a sample imaging camera are also available upon request.
The new TR-PROBE is a compact, robust THz-Raman® probe that enables in-situ reaction or process monitoring. The TR-PROBE can be configured with a variety of immersion or contact probe tips, a convenient vial holder, tablet holder, or a steerable collimated beam (see sample options on previous page).
The XLF-CLM is configured for Benchtop use and offers an optional vial/cuvette sample holder for fast, easy measurements. The system also comes with a standard cage mounting plate (centered on the collimated output beam) to allow for customized collection optics or easy integration into a customized system. The XLF-CLM includes a SureLock™ 785nm, 850nm, or 976nm laser source, notch filters, and optional circular polarization.