UCF researcher Debashis Chanda is an expert in infrared imaging. University of Central Florida.
Debash Debashis Chanda, a researcher at the University of Central Florida and a professor at the Center for Nanoscience and Technology, has developed a new technique to detect photons—an elementary particle that moves from visible light to radio frequencies and plays an important role in cellular communication.
This advancement is likely to lead to more precise and efficient technology in a variety of fields, from improving medical imaging and communication systems to enhancing scientific research and possibly even enhancing security measures.
Photon detection typically relies on changes in the amplitude of voltage or current modulation. But Chanda has developed a method to detect photons by modulating the frequency of an oscillating circuit, paving the way for ultra-sensitive photon detection.
Chanda's method uses a special phase change material (PCM) that, when light comes into contact with it, changes shape so that the electrical rhythm is stable, or a stable circuit oscillation. When a photon hits a material, it changes the speed of the rhythm, or changes the frequency of the oscillation. The degree of change in rhythm depends on the intensity of the light, similar to the human voice will change the sound of the radio.
This new development was recently published in the journal Advanced Functional Materials.
8 Long-wave infrared (LWIR) detection in the 12 micron wavelength range is of great importance in the fields of astronomy, climate science, materials analysis, and safety. However, due to the low energy of photons, LWIR detection at room temperature has been a long-term challenge.
The available LWIR detectors can be broadly divided into two types: cooled and uncooled, both of which have their own limitations.
While cooled detectors provide excellent detection capabilities, they require cryogenic cooling, which makes them expensive and limits their practical applications. Uncooled detectors, on the other hand, can operate at room temperature, but have low detection rates and slow response due to the higher thermal noise inherent in room temperature operation. Low-cost, high-sensitivity, and fast infrared detector cameras continue to face scientific and technical challenges.
This is the main reason why LWIR cameras are not widely used, except in the Ministry of Defense and specific space applications.
"Unlike all existing photon detection schemes, where optical power changes the amplitude of a voltage or current (amplitude modulation – AM), in the proposed scheme, the impact or event of a photon modulates the frequency of the oscillating circuit and is detected as a frequency shift, providing inherent robustness to noise that is essentially AM," Chanda said. ”
Our FM-based approach yields excellent room temperature noise equivalent power, response time, and detection capability," Chanda said. "This FM-based photon detection concept can be implemented in any spectral range based on other phase change materials. ”
"Our findings use this novel FM-based detector as a unique platform for the fabrication of low-cost, high-efficiency uncooled infrared detectors and imaging systems for a variety of applications such as remote sensing, thermal imaging, and medical diagnostics," Chanda said. "We strongly believe that with the right industrial-scale packaging, performance can be further improved. ”
This concept developed by the Chanda group provides a paradigm shift for high-sensitivity, uncooled LWIR detection, as noise limits detection sensitivity. This result is expected to provide a new uncooled LWIR detection scheme with high sensitivity, low cost, and easy integration with electronic readout circuits without the need for complex hybridization.