Researchers in Thailand have developed a cost-effective standoff Raman spectroscopy system using a night-vision intensified spectrometer and digital correction algorithms. The system reliably detects chemical compounds at distances up to 60 meters with high spectral resolution.
Affordable Innovation in Remote Chemical Detection
A team of scientists from Prince of Songkla University and the National Astronomical Research Institute of Thailand (NARIT) has unveiled a novel hybrid optical-digital system that could significantly reduce the cost of long-range Raman spectroscopy. Using a night-vision (NV) intensified spectrometer in place of the traditionally expensive intensified charge-coupled device (ICCD) cameras, the researchers achieved precise chemical identification from distances of up to 60 meters—at a fraction of the cost (1).
Their work, published in Optics Express, is titled "Hybrid Optical-Digital Design for Cost-Effective Standoff Raman Detection System Utilizing a Night-Vision Intensified Spectrometer". The authors—Sukrit Thongrom, Panuwat Pengphorm, Pruet Kalasuwan, Paphavee van Dommelen, and Chalongrat Daengngam—designed the system using commercially available components, enhanced with 3D-printed parts for rapid prototyping and flexibility (1).
Why Raman Spectroscopy?
Raman spectroscopy identifies molecules by analyzing the way light scatters after interacting with molecular vibrations, creating a spectral “fingerprint.” In standoff Raman systems, this process is performed from a distance, allowing non-invasive detection of hazardous or hard-to-reach materials, including explosives and chemical agents. The method has wide-reaching applications—from forensic science and environmental monitoring to process analysis, and planetary exploration (1–3).
However, traditional systems rely on ICCD cameras, which can cost upwards of $100,000. These high-end cameras are essential for amplifying weak Raman signals, especially when laser power is limited by safety or material damage thresholds. The researchers saw an opportunity to bypass these cost barriers using components adapted from night vision technology (1).
Night Vision Meets Spectroscopy
While NV intensifier tubes lack the sensitivity and resolution of ICCDs, they are dramatically more affordable—typically priced between $2000 and $5000. The researchers addressed the performance gap with a “hybrid optical-digital design” approach (1).
They first optimized the optical path using a Schmidt-Cassegrain telescope (SCT) and two focal-reducing lenses (L1 and L2) to maximize light throughput and coupling into the spectrograph. A thermoelectrically cooled complementary metal oxide semiconductor (CMOS) camera—typically used in astronomy—was integrated to reduce noise during long exposure times (1).
Then, a digital post-processing technique was applied using a non-blind deconvolution algorithm. This algorithm compensates for the resolution degradation introduced by the NV intensifier, restoring spectral resolution from approximately 1.9 nm down to 1.00 ± 0.09 nm—fine enough to distinguish nitrate groups in similar compounds (1).
Real-World Results
The prototype system, compactly built in a 3D-printed housing, successfully detected Raman signatures of compounds such as urea, ammonium nitrate (NH₄NO₃), barium nitrate (Ba(NO₃)₂), sodium nitrate (NaNO₃), calcium nitrate (Ca(NO₃)₂), and barium sulfate (BaSO₄) at distances between 30 and 60 meters (1).
Critically, the system achieved a signal-to-noise (S/N) ratio of about 102, a performance level comparable to far more expensive systems. By increasing exposure time, the researchers were able to capture weaker signals from more distant targets without introducing excessive noise—a key breakthrough for practical field applications (1).
The integration of off-the-shelf components and digital signal recovery makes this system not only cost-efficient but also highly adaptable. Mounted on a portable metal cart with azimuth and altitude adjustments, the setup is suited for real-time field deployment (1).
A Path Forward for Low-Cost Spectroscopy
This research opens new possibilities for standoff spectroscopy in resource-limited environments, where traditional ICCD-based systems are economically unfeasible. From border security to environmental hazard detection, the affordable yet precise NV-based Raman system may help democratize access to powerful spectroscopic tools (1–3).
The study represents a compelling intersection of consumer-grade night vision, astronomy hardware, and advanced digital processing—an innovation likely to inspire similar cost-reduction strategies in other scientific instrumentation.
References
(1) Thongrom, S.; Pengphorm, P.; Kalasuwan, P.; van Dommelen, P.; Daengngam, C. Hybrid Optical-Digital Design for Cost-Effective Standoff Raman Detection System Utilizing a Night-Vision Intensified Spectrometer. Opt. Express 2025, 33 (5), 11757–11774. DOI:
(2) Marteau, P.; Zanier-Szydlowski, N.; Aoufi, A.; Hotier, G.; Cansell, F. Remote Raman Spectroscopy for Process Control. Vib. Spectrosc. 1995, 9 (1), 101–109. DOI:
(3) Angel, S. M.; Gomer, N. R.; Sharma, S. K.; McKay, C. Remote Raman Spectroscopy for Planetary Exploration: A Review. Appl. Spectrosc. 2012, 66 (2), 137–150. DOI:
