IS-Instruments’ Notus gas Raman instrument is engineered to deliver rapid, stable in situ compositional evaluation of complex gas mixtures.
In this interview, Dr Michael Foster, Co-Founder and Director at IS-Instruments, details how Raman spectroscopy, hollow-core microstructured optical fibers, and robust optical design are helping address the constraints of conventional gas evaluation techniques, while supporting applications from industrial process monitoring to advanced fusion energy technologies.
Could you outline IS-Instruments’ work in Raman gas evaluation and explain the original needs that led to the Notus gas Raman instrument being developed?
IS-Instruments specializes in cutting-edge optical instrumentation, including Raman spectroscopy systems for harsh measurement environments. Our work in gas Raman analysis was driven by the need for quicker, more direct compositional measurements in applications where standard methods can be slow, maintenance-intensive, or challenging to integrate near the process.
Notus was engineered to deliver stable, in situ Raman gas analysis, providing immediate insight into gas composition. The goal was to develop a miniaturized, robust instrument that can monitor several gas species concurrently, without relying on chromatographic separation, carrier gases, or routine consumable replacement.
Image Credit: IS-Instruments
Gas analysis is crucial in applications where composition impacts process performance, product quality, safety, or regulatory compliance. What types of measurement difficulties were you aiming to address with Notus?
While GC remains the industry standard for numerous gas-evaluation applications, it is inherently batch-based and requires carrier gases, consumables, and routine maintenance. In workflows where gas composition can shift quickly, the time between sampling and result availability can limit operational responsiveness.
Notus was engineered to fulfill the need for stable, in situ gas evaluation capable of providing real-time compositional insight. Unlike alternative Raman-based gas analyzers, we focused on developing a robust platform that can perform continuous, low-maintenance measurements while bypassing the workflow complexity linked to chromatographic separation methods.
How does Raman spectroscopy allow Notus to deliver concurrent, species-specific measurements in complex gas mixtures?
Raman spectroscopy quantifies the interaction between laser light and molecular vibrations. Each gas species generates a characteristic Raman signature, effectively providing a spectral fingerprint. This enables the identification and quantification of multiple components within a gas mixture from a single spectrum.
For Notus, this capability enables simultaneous monitoring of multiple gases rather than individual measurements. This is especially important for complex or changing mixtures, where understanding the relationships between distinct species is as critical as quantifying a single component.
Many conventional gas analysis methods rely on consumables, sample preparation, or sequential workflows. How does an in-line Raman methodology change how users monitor gas composition?
The crucial difference is that users no longer have to wait for results and can, instead, constantly monitor the workflow. Standard methods frequently involve sample handling, consumables, and sequential analytical processes. Conversely, an in-line Raman system measures multiple gas species simultaneously, providing instantaneous compositional information.
This provides operators with immediate insight into process behavior, allowing for quicker decision-making, greater process control, and lower dependence on consumables and regular maintenance. Instead of taking periodic snapshots of a process, users obtain a constant view of what is happening as conditions change.
Notus employs hollow-core microstructured optical fibers to extend the laser interaction path. Could you explain how this design enhances sensitivity for gas-phase Raman measurements?
Measuring gas phases with Raman presents inherent challenges, as gases contain far fewer molecules per unit volume than liquids or solids, generating weaker Raman signals. Notus addresses this by employing hollow-core microstructured optical fibers, allowing the laser light and gas sample to interact over a substantially longer distance.
Within the hollow core, the light is guided directly through the gas, effectively extending the measurement path while maintaining instrument compactness. This lengthened interaction increases the collection of Raman scattering events, delivering higher signal strength and improved measurement sensitivity.
In practical terms, this facilitates the dependable measurement of reduced gas concentrations while maintaining the benefits of a miniaturized in situ Raman analyzer.
Image Credit: IS-Instruments
What were the primary technical difficulties in developing a robust gas Raman instrument for instantaneous use?
The primary challenge was achieving adequate sensitivity and stability in a format suitable for real-world operation. Due to weak gas Raman signals, the optical design, laser delivery, signal collection, and detector performance must all work together efficiently.
A second challenge was robustness. An instrument designed for instantaneous monitoring must provide reliable data over extended periods, often in non-ideal lab environments. This necessitates maintaining optical alignment, managing background signals, preserving calibration stability, and ensuring consistent operation with low user intervention.
Which applications are proving particularly well-suited to Notus?
Notus is especially ideal for applications where gas composition requires continuous monitoring or where quick composition changes are crucial. This includes gas blending, process monitoring, quality control, and modified-atmosphere packaging, where users need confidence in the accuracy and stability of the gas mixture.
In addition, the platform provides value in specialist research settings that require concurrent tracking of multiple gas species, especially when users want to minimize sample handling or avoid consumables-heavy processes. The capacity to produce instantaneous compositional data delivers operational advantages across both industrial and research environments.
IS-Instruments has worked with UKAEA through the Fusion Industry Program to investigate Raman spectroscopy for tritium detection.* How did that project build on the existing Notus platform?
The UKAEA Fusion Industry Program project investigated how the core Notus methodology could be applied to the specific challenge of tritium detection and monitoring. The existing platform already provided the key advantages of Raman gas evaluation: concurrent species measurement, in situ monitoring, and decreased reliance on consumables.
The fusion application builds on that foundation while introducing additional technical requirements. Hydrogen isotopologues are closely related species, and differentiating between them at low concentrations is crucial.
The project therefore focuses on adapting and optimizing the Raman methodology to satisfy the sensitivity, selectivity, and dependability requirements for fusion-relevant gas environments. As of 2026, our work with the UKAEA FIP is ongoing.
What makes measuring hydrogen isotopologues, including tritium, at low concentrations especially difficult in complex gas mixtures?
Hydrogen isotopologues are challenging because they differ in mass despite their chemical similarity, leading to small variations in their Raman spectra. Detecting and differentiating these species requires elevated spectral resolution, robust signal sensitivity, and meticulous control of background noise.
The challenge increases at low concentrations and in complex gas mixtures, where overlapping signals or interfering species may be present. Tritium involves safety and containment standards, meaning the selected analytical strategy must be not only sensitive and selective but also appropriate for controlled, dependable operation under radioactive conditions.
Looking ahead, how do you see advanced Raman spectroscopy supporting both industrial gas monitoring and future fusion energy technologies?
Advanced Raman spectroscopy has high potential whenever users require rapid, dependable, multi-species gas evaluation without the complexity of conventional workflows. In industrial environments, it can support improved process control, quicker decision-making, decreased downtime, and less reliance on consumables.
For fusion energy, Raman spectroscopy could play a crucial role in monitoring hydrogen isotopologues and supporting safe, efficient fuel-cycle management.
As fusion technologies move closer to deployment, robust analytical instruments will be needed to deliver instantaneous insight into complex gas systems. Raman provides a promising route because it combines molecular specificity with concurrent measurement and the potential for in situ operation.
Where can readers find more information?
Articles about the gas Raman system can be found in the news section of our website: https://is-instruments.com/news/.
About Dr Michael Foster
I am the Co-Founder and Director of IS-Instruments, where I lead the development of advanced Raman and optical-sensing technologies for industrial and research applications. With a background in space instrumentation and remote sensing, I have focused my career on translating high-precision optical measurement techniques into robust tools for real-world environments.
At ISI, I am central to advancing Raman spectroscopy for challenging applications, including gas analysis, process monitoring, and fusion research. I have been involved in the development of several instruments from initial concept to market, including our ODIN system and HES Raman spectrometers.
About IS-Instruments
Founded in 2010, IS-Instruments is a UK-based developer and manufacturer of spectrometers, laser-based instrumentation, and bespoke LIDAR solutions for scientific, industrial, and research applications.
Specialising in Raman spectroscopy, the company draws on extensive expertise in optical engineering and system integration to develop technologies for applications such as process monitoring, gas analysis, fusion energy, pharmaceuticals, healthcare, aerospace, and environmental monitoring.
Its portfolio includes the Notus Raman gas analyser, the Odin deep-UV spectroscopy platform, and freeze-drying monitoring technologies.
Working closely with industry, academia, and government organizations, IS-Instruments combines scientific innovation with practical engineering to deliver robust instrumentation for demanding real-world environments.
For more information, visit http://is-instruments.com/.
* This project has been supported by the UK Atomic Energy Authority through the Fusion Industry Programme. The Fusion Industry Programme is stimulating the growth of the UK fusion ecosystem and preparing it for future global fusion powerplant market.
More information about the Fusion Industry Programme can be found online: https://ccfe.ukaea.uk/programmes/fusion-industry-programme/
This information has been sourced, reviewed, and adapted from materials provided by IS-Instruments Ltd.
For more information on this source, please visit IS-Instruments Ltd.
Disclaimer: The views expressed here are those of the interviewee and do not necessarily represent the views of AZoM.com Limited (T/A) AZoNetwork, the owner and operator of this website. This disclaimer forms part of the Terms and Conditions of use of this website.