Extend the range of Raman spectroscopy with THz-Raman®

Ondax’s 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.

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 Extend the range of Raman spectroscopy with THz-Raman®

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

Raman spectroscopy with THz-Raman®

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.

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.

The TR-WPS Automated Well-plate Measurement System combines high throughput screening (HTS) capability with our patented low-frequency/THz-Raman® technology to automatically capture the entire Raman spectrum from -800 cm-1 to +2800 cm-1 for common well-plate measurements. Ideal for screening and identification of polymorphic compounds and co-crystals, or quantifying degree of crystallinity in pharmaceuticals,the WPS has been designed to be fully automated, from sample insertion to data generation. The sample is excited with a 785 nm Ondax CleanLine™ laser from below the well in an inverted microscope format. A plate auto-focusing system ensures measurement repeatability, and an integrated vision system with polarized light detection can be used to determine areas of interest within each well.
The WPSTM Application Software Interface has a highly intuitive GUI with a layered design, enabling fast learning and simplified operation, while providing extensive additional functionality in advanced mode.



Sample Accessories for the TR-PROBE and TR-BENCH

THz-Raman Microscope

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


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


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

THz-Raman Well Plate System

TR-WPS  Automated Well Plate System, compatible with standard 6, 12, 24, 48, 96, 384, or 1536 well plates, as well as custom substrates.


NEW Transmission Raman Accessory for the TR-PROBE


NEW Microscope Adapter Accessory for the TR-PROBE


  • 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
Spectrometer*: 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

For more information on Polymorph Identification click here

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

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

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

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


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


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

Ammonium Nitrate

Ammonium Nitrate

Low frequency Raman spectra of Theophylline amorphous-crystalline transition

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