Case Study: SWIR Optical Filters for Pipeline Contaminant Detection
Chroma Technology collaborated with a sensor manufacturer in the oil and gas industry that was facing challenges in contaminant detection within pipelines. By designing custom short-wave infrared (SWIR) optical filters with precise band widths, cut-ons, and cut-offs — and optimizing coatings for durability — Chroma enabled the sensor to effectively isolate chemical signatures in field conditions. The result was a highly optimized, rugged sensor system that met the customer’s performance and environmental demands.
The customer required spectral precision and rugged performance in challenging field environments.
The Challenge
The customer’s sensor system demanded isolation of specific SWIR wavelengths associated with chemical contaminants, along with precise spectral characteristics including bandwidth, cut-on, and cut-off performance, all while remaining compatible with a compact instrument design and tight optical paths. Off-the-shelf filters were unable to meet this combination of spectral, mechanical, and environmental requirements.
The Solution
Chroma Technology leveraged its expertise in SWIR filter design to develop a customized solution. The team adapted existing high-performance SWIR technology and collaborated closely with the customer to refine and optimize the design for real-world instrument conditions. Chroma also provided guidance on instrument design adjustments to maximize performance. This collaborative process ensured seamless integration into the customer’s sensing platform
Key features included:
- High transmission – Maximum light throughput in target bands to preserve signal strength to the detector
- Sharp spectral transitions – Steep cut-on/off slopes for clean separation between passbands
- Deep out-of-band blocking – Tight rejection outside the passband, eliminating noise from adjacent wavelengths
- Precise band placement – Exact wavelength positioning improves signal-to-noise and detection accuracy
The implementation steps were:
- Define target wavelengths based on contaminant signatures.
- Optimize coatings for beam shape and angle of incidence.
- Ensure compatibility with compact optical paths.
- Utilize sputter-coated filters for enhanced thermal and mechanical durability.
The Results
Results of the project were:
- Improved system-level optimization through collaborative redesign
- Precise detection of contaminants at targeted SWIR wavelengths
- Successful validation testing with performance meeting customer expectations
Conclusion
This project demonstrated that early collaboration and iterative refinement are key to delivering optimized optical solutions. Rugged sputtered coatings proved essential for industrial durability, while precise spectral engineering enabled accurate detection of chemical signatures. The success of this engagement has laid the groundwork for continued partnership and future filter development.
About Chroma Technology
Chroma Technology is a leading manufacturer and OEM supplier of high performance optical filters used in a wide range of applications, such as communications, inspection and metrology, astronomy, life sciences and health care, microscopy, calorimetry, machine vision, and Raman spectroscopy. Chroma offers an extensive selection of optical filter sets and filter accessories, as well as custom solutions tailored to customer-specific needs
For more information or a quotation for this or other Chroma products, contact IL Photonics.