Renishaw Announces Time-Resolved Raman Spectroscopy (TRRS) Integration

In a recent press release, Renishaw announced the launch of a new innovation in Raman spectroscopy, which is the integration of time-resolved Raman spectroscopy (TRRS) into their inVia™ confocal Raman microscope (1,2). According to the company, this technique is designed to allow researchers and engineers to overcome the long-standing challenge of sample fluorescence, unlocking Raman spectra from samples previously deemed unmeasurable (1). By exploiting the significant difference in interaction times between these two phenomena, TRRS successfully separates the Raman signal from the fluorescence background, thereby enabling the measurement of high-quality Raman spectra from samples that are otherwise impossible to analyze using conventional Raman systems (1).

TRRS employs a pulsed laser synchronized with an ultra-fast detector. Following each laser pulse, the detector records the time taken for photons to arrive (1). By incorporating a dispersive element, such as a grating, the system measures the arrival time of photons relative to their energy or wavenumber (1). When repeated over many laser pulses, this process generates a histogram detailing photon arrival time versus wavenumber, which includes photons associated with both Raman scattering and fluorescence (1).

Renishaw has developed TRRS systems over a decade, utilizing patented technologies to improve throughput, prevent spectral artefacts, and simplify data extraction. Renishaw’s TRRS system integrated a high repetition rate picosecond pulsed 532 nm laser with a newly released single-photon avalanche diode (SPAD) array detector (1). This SPAD array is capable of detecting single photons and precisely recording their arrival time relative to the laser pulse. Within the spectrometer, a grating disperses the light across the SPAD array, enabling the observation of photon timing across different wavenumbers.

There are several applications areas where TRRS could be used. Because the technique provides clear Raman spectra from challenging fluorescent samples, it is ideal for several chemicals, polymers, pigments, food, and materials. The press release highlights four examples where TRRS integration with their Raman microscope would be helpful.

The first is Kapton. Because this polyimide film is highly fluorescent, it’s difficult to collect useful Raman information using conventional 532 nm and 785 nm excitations. TRRS successfully separates the information, providing comprehensive Raman data (1).

For food analysis, sesame oil was highlighted as another example. Both cooking and lubricating oils often exhibit broadband fluorescence, making conventional analysis difficult. For sesame oil, fluorescence begins to increase after 300 picoseconds (ps) and dominates the signal after 800 ps, meaning that summing the data (as conventional Raman does) would obscure the Raman signal (1). TRRS, using its proprietary algorithm, extracts a comprehensive spectrum, revealing very weak bands that would otherwise be lost (1).

Third, Renishaw highlighted how this integration can analyze specific pigments that can be masked by other pigments that absorb light and case strong fluorescence, using Legos as an example. While conventional Raman struggled, providing fluorescence-dominated spectra, TRRS delivered usable, comprehensive Raman information from all tested bricks, allowing identification of the ABS spectrum and specific pigments like phthalocyanine blue (1). It was also able to determine that the transparent brick was similar to a cellulose acetate derivative (1).

Finally, this integration is ideal for high-temperature samples. Raman spectroscopy is typically challenged by broad black-body emission at high temperatures. For sapphire at 1500 °C, conventional methods only resolved the strongest band with a signal-to-noise ratio of approximately 1:1 (1). Because TRRS only isolates and extracts data collected during a very small duty cycle immediately following the laser pulse, it significantly reduces the overall contribution of black-body emission to the background. This enabled the TRRS integration to easily measure sapphire up to 1500 °C, resolving all Raman bands and allowing accurate calculation of phonon temperature dependence (1).

References

1. SPIE, Singular Photonics and Renishaw Shed New Light on Spectroscopy. Optics.org. Available at: https://optics.org/press/6228 (accessed 2025-12-18).
2. Renishaw, Renishaw Introduces New Functionality to its inVia™ Confocal Raman Microscope. Renishaw. Available at: https://www.renishaw.com/en/renishaw-introduces-new-functionality-to-its-invia-confocal-raman-microscope--47838 (accessed 2025-12-18).