Researchers at the University of Michigan have developed an uncooled, highly sensitive infrared (IR) detector with an embedded bowtie nano-antenna. The performance of conventional IR detectors is limited by thermal noise. The sensitivity of these detectors is commonly improved by cooling them (cryogenic detectors). However, cooling of IR detectors entails high space and power requirements rendering cooled detectors undesirable for many applications.
The uncooled, highly sensitive infrared detector with an embedded bowtie nano-antenna developed at the University of Michigan overcomes the issues associated with conventional and/or cooled IR detectors. The IR detector is implemented using a high impedance nano-antenna with an embedded matching network. The bowtie nano-antenna is operated at its anti-parallel resonance and loaded with a small low-bandgap InGaAsSb PN-junction. The structure is optimized for maximum power transfer and significant field enhancement at its terminals for a desired frequency band where the maximum quantum efficiency of InGaAsSb is observed. Compared to conventional detectors, the bowtie-antenna-embedded detector improves detectivity by a factor approximately equal to the antenna field enhancement factor (greater than 20). The proposed detector, or a small array of such detectors, can be utilized for very high-resolution focal plane arrays of IR imagers with polarimetric capabilities. Multiple antenna-embedded IR detectors can be connected in a variety of configurations to achieve desired output voltage and current values. The design’s low pixel size (under 1 square micron) is two to three orders of magnitude smaller than current state-of-the-art designs. Further, the detectors are polarization sensitive, i.e., the nano-antennas can be configured to collect different polarizations of incoming radiation, thereby allowing for the discernment of radiation sources.
- Heat sensors
- IR imagers for medical and industrial applications
- Night vision for automotive and military applications
- 3-D IR cameras for gaming
- Uncooled—low energy and area
- High sensitivity
- Small footprint
- High resolution
- Low pixel size (under 1 square micron)
- Polarization sensitivity
- Support for multiple connection configurations