Extend the range of Raman spectroscopy with THz-Raman®

Ondax’sLow Frequency THz-Raman Spectroscopy Systems patented 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. The THz-Raman spectral region covers both Stokes and anti-Stokes signals from ±5 cm-1 to 200 cm-1, (or 150 GHz to 6 THz), which contain important structural information about the molecule or crystal lattice. 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.

Download the Ondax Raman Products Brochure

See What You’ve Been Missing – More Data, Better Sensitivity and Reliability

THz-Raman spectra show clear differentiation of structural attributes of the material, ideal for identification and analysis of polymorphs, raw material sources, defects & contamination, crystal formation and orientation, phase monitoring and synthesis methods. Applications include pharmaceuticals, explosives, narcotics, nano- and bio-materials, semiconductors, photovoltaics, and petrochemicals.

By adding both low-frequency and anti-Stokes signals to the traditional fingerprint, THz-Raman systems boost overall Raman intensity and improve SNR.. And the symmetrical nature of the anti-Stokes signals act as a confirmation of Stokes peaks, while providing an inherent calibration reference that improves overall confidence and reliability.

One Sample, One System, One Answer

Low Frequency Raman Spectrum of Carbamazepine

Full Raman spectrum of the pharmaceutical Carbamazepine showing both the THz-Raman “Structural Fingerprint” and traditional “Chemical Fingerprint” regions. Note higher intensity, stronger differentiation, and inherent symmetry of THz-Raman signals.

Combining both composition and structural analysis eliminates the need for multiple samples and instruments, lowering capital, training and maintenance costs. These compact plug-and-play platforms can be integrated with virtually any lab-grade microscope or Raman system. With excitation wavelengths ranging from 488nm to 976nm, and a wide range of options and compatible spectrometers to choose from, an Ondax THz-Raman® system can be optimized to match any application.

Plug-and-Play upgrade to your existing microscope or Raman system, or configurable as a complete custom system
All TR-Series THz-Raman®  modules are ultra-compact and simple to connect via fiber to almost any spectrometer or Raman system. A high-power, wavelength-stabilized, single-frequency laser source is precisely matched to the ultra narrow-band ASE, beamsplitter and notch filters to assure maximum throughput and exceptional attenuation (>OD 9) of the excitation source. Systems are available in 532nm, 633nm, 785nm, 808nm, 976nm and 1064nm excitation wavelengths..

Low Frequency THz-Raman Microscope

TR-MICRO THz-Raman® Microscope Platform mounted on Leica DM2700 Microscope

The TR-PROBE is a compact, robust THz-Raman® probe that enables in-situ reaction or process monitoring, and can also be flexibly configured with a variety of sample interface accessories, including immersion or contact probe tips, a convenient vial/tablet holder, a Transmission Raman adapter, a microscope mount, or a steerable non-contact optic (see options below). A separate CleanLine™ laser provides ASE-free excitation via a multimode fiber, enabling the probe to operate in harsher environments where electrical connections are not permitted.

The TR-BENCH is configured for benchtop use and offers a similar range of interchangeable sample interface accessories 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. Options include circular polarization or a dual-port/dual polarization output for simultaneous measurement of both S and P polarizations.

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. Linear polarization is standard, circular polarization is optional.

Low Frequency THz-Raman Probe

TR-PROBE In-situ THz-Raman® Probe with optional Ballprobe tip

Low Frequency/THz-Raman Spectroscopy Modules

TR-BENCH Benchtop THz-Raman® Module with optional vial/cuvette/tablet sample holder


TR Sample Accessories

Sample Accessories for the TR-PROBE and TR-BENCH

  • Polymorphic structure identification and monitoring
  • Amorphous-to-crystalline transformation
  • Structural studies of nano-and bio-materials
  • In-situ Crystallization and Reaction Monitoring
  • Trace detection and source attribution of explosives/hazmat/drugs
  • Forensics studies
  • Geological specimen analysis and gemology
  • Fast collection of THz-Raman/Low frequency spectra
  • Simultaneous Stokes and anti-Stokes signals improve SNR while providing inherent calibration reference
  • High Optical Density (>OD8) with extremely high throughput
  • Ultra-compact footprint, plug-and-play operation, fiber coupled output
  • Compatible with most commercial spectrometers, microscopes and Raman systems
  • Integrated ASE filtering with high-throughput 90/10 dichroic beamsplitter
  • Available at 532, 633, 785, 850, 976nm, and 1064nm.


Parameter Units Specification
Wavelength nm 532 785/850 976
Power at sample port (min) mW 50 to 250* 100 300
* Specify power level at time of order
Fixed Grating Spectrometer Tunable Grating Spectrometer
Spectral Range (typical) -200cm-1 to +2200cm-1 0-1100 nm (w/Si Detector)
Spectral Resolution 2.5cm-1 to 4cm-1 1.25cm-1 or greater
Computer Interface  USB USB
Polymorph ID

For more information on Polymorph Identification click here

Low frequency/THz-Raman Spectra of CBZ

Low Frequency/THz-Raman spectra of CBZ Polymorphs Forms 2 and 3, plus Hydrate

Low frequency THz-Raman spectra of common APIs

Complete Raman spectra of common APIs. Note stronger intensity in THz-Raman region

Explosives Detection

For more information on Explosives Detection and Source Attribution click here

HMTD Low Frequency THz-Raman Spectra

HMTD, a common homemade explosive (HME), showing strong THz-Raman signals that improve detection sensitivity and reliability. (Sample courtesy Dr. Brian Leigh, UCSD).

HMTD Low Frequency THz-Raman Spectra
TATP Low Frequency/THz-Raman Spectra

TATP, another well known HME. (Sample courtesy Dr. Brian Leigh, UCSD).

Ammonium Nitrate Low Frequency/THz-Raman Spectra

Ammonium Nitrate

Crystallization and Reaction Monitoring

For more information on Crystallization and Reaction Monitoring click here

Theophylline transformation low frequency waterfall spectra

Low frequency Raman spectra of Theophylline amorphous-crystalline transition

Transformation profile of Theophylline based on Low frequency Raman spectra

Transformation profile of Theophylline based on Low frequency Raman spectra