Ultra-Compact Mid-Wave Infrared Photodetector Pixels Achieve High Efficiency

On April 2, 2025, researchers Sreeja Purkait, Noah Mansfield, Yadviga Tischenko, Amogh Raju, William Reggio, Daniel Wasserman, and Viktor Podolskiy published a study introducing ultra-compact mid-wave infrared photodetector pixels with high external efficiency, achieved through lateral cavity-enhanced guided mode resonance structures.

Researchers designed ultra-compact mid-wave infrared photodetector pixels using guided mode resonance structures to confine light within a thin absorber layer. A hybrid cavity-guided mode resonance further confined the mode laterally, enabling pixel dimensions of nearly twice the free space wavelength. The design predicts an external efficiency of approximately 50%, offering benefits such as low dark current, room temperature operation, and small size. This advancement paves the way for compact mid-wave infrared pixels with enhanced performance.

At the forefront of this revolution are plasmonic materials, which manipulate light at the nanoscale through surface plasmons—oscillations of electrons that occur at the interface between metals and dielectrics. These materials enable the creation of ultra-thin detectors capable of detecting even the faintest infrared signals. By integrating plasmonic structures with semiconductors like InAsSb, scientists have achieved remarkable improvements in responsivity and operating temperature ranges.

Guided-Mode Resonance and Beyond

Another breakthrough comes from guided-mode resonance (GMR) technology, which uses periodic nanostructures to trap light within specific wavelengths. This approach has been particularly effective in mid-wave and long-wave infrared detection, enabling the development of room-temperature detectors that are both compact and highly sensitive. Recent studies have demonstrated the potential for all-epitaxial integration of these structures, paving the way for scalable manufacturing and widespread adoption.

Applications Across Industries

• The implications of these advancements extend far beyond the laboratory. Infrared detection is critical in thermal imaging, environmental monitoring, and space-based sensing. For instance:
• Urban Climate Studies: Thermal infrared remote sensing is increasingly used to monitor urban heat islands and assess the impact of climate change on cities.
• Vegetation Monitoring: Advanced infrared sensors enable researchers to study vegetation health and precisely track ecosystem changes.
• Sea Surface Temperature: Accurate measurement of sea surface temperature from space is essential for understanding ocean dynamics and predicting weather patterns.

Looking Ahead

As the field continues to evolve, researchers are exploring new materials and architectures to push the boundaries of infrared detection even further. The integration of machine learning algorithms with these advanced detectors promises to enhance their functionality, enabling real-time data analysis and adaptive sensing capabilities.

In conclusion, the fusion of condensed matter physics with nanotechnology is driving a transformative shift in infrared detection. These innovations not only advance our scientific understanding but also hold the potential to address some of the most pressing challenges of our time—from climate change to urban sustainability. As this technology matures, its impact will be felt across industries and disciplines, ushering in a new era of global observation and environmental stewardship possibilities.