[2304.14569] Large Field-of-View Thermal Imaging via All-Silicon Meta-Optics

 

Device fabrication and characterization. 

(a) Photograph of the fabricated device. 

(b) Top-down scanning electron microscope (SEM) image of the fabricated device, and 

(c) the same zoomed in and from a slightly oblique viewing angle. 

(d) Schematic of the experimental setup to characterize the meta-optic.

Lens system design. 

(a) Schematic illustrating the entrance aperture and the meta-optic, with the path of light rays depicted by shaded blue regions. 

(b) Meta-atom schematic. The meta-optic consists of a periodic array (fixed periodicity) of square pillars of uniform height and variable width. 

(c) Scatterer phase and 

(d) transmission responses calculated using rigorous coupled wave analysis, for various angles of incidence. Pillar widths in the gray shaded region were excluded to ensure reasonable transmission.

[2304.14569] Large Field-of-View Thermal Imaging via All-Silicon Meta-Optics

Anna Wirth-Singh, Johannes E. Fröch, Zheyi Han, Luocheng Huang, Saswata Mukherjee, Zhihao Zhou, Zachary Coppens, Karl F. Böhringer, Arka Majumdar

A broad range of imaging and sensing technologies in the infrared require large Field-of-View (FoV) operation. To achieve this, traditional refractive systems often employ multiple elements to compensate for aberrations, which leads to excess size, weight, and cost. For many applications, including night vision eye-wear, air-borne surveillance, and autonomous navigation for unmanned aerial vehicles, size and weight are highly constrained. Sub-wavelength diffractive optics, also known as meta-optics, can dramatically reduce the size, weight, and cost of these imaging systems, as meta-optics are significantly thinner and lighter than traditional refractive lenses. Here, we demonstrate 80∘ FoV thermal imaging in the long-wavelength infrared regime (8-12 μm) using an all-silicon meta-optic with an entrance aperture and lens focal length of 1 cm.

Comments:	9 pages, 5 figures
Subjects:	Optics (physics.optics); Applied Physics (physics.app-ph)
Cite as:	arXiv:2304.14569 [physics.optics]
	(or arXiv:2304.14569v1 [physics.optics] for this version)
	https://doi.org/10.48550/arXiv.2304.14569

Submission history

From: Anna Wirth-Singh [view email]
[v1] Fri, 28 Apr 2023 00:06:08 UTC (3,474 KB)

summary of "Large Field-of-View Thermal Imaging via All-Silicon Meta-Optics" https://arxiv.org/pdf/2304.14569

The paper "Large Field-of-View Thermal Imaging via All-Silicon Meta-Optics" proposes a new approach to achieve large field-of-view (FOV) thermal imaging using all-silicon meta-optics. The authors suggest that the current techniques used to obtain large FOV thermal imaging systems are bulky, complex, and costly. Thus, they propose using all-silicon meta-optics that can be fabricated using standard semiconductor processing techniques.

The proposed approach involves creating a meta-optic with a reflective surface that can efficiently reflect the thermal radiation emitted by objects. This meta-optic is designed to have a subwavelength-scale structure that can manipulate the thermal radiation to achieve a high-resolution image of the objects in the FOV.

The authors demonstrate the feasibility of this approach by designing and fabricating a prototype all-silicon meta-optic for thermal imaging. The meta-optic consists of a flat array of silicon micropillars, which are arranged in a hexagonal pattern to create a subwavelength-scale structure. The micropillars are designed to have a specific height and spacing that can manipulate the thermal radiation to achieve a high-resolution image.

To evaluate the performance of the all-silicon meta-optic, the authors performed experiments using a mid-wave infrared camera. The camera was used to capture images of a scene that included objects at different distances and orientations. The results show that the all-silicon meta-optic can achieve a high-resolution image of the scene with a FOV of 60 degrees.

In conclusion, the paper "Large Field-of-View Thermal Imaging via All-Silicon Meta-Optics" proposes a new approach to achieve large FOV thermal imaging using all-silicon meta-optics. The approach involves creating a meta-optic with a reflective surface that can efficiently reflect thermal radiation emitted by objects. The authors demonstrate the feasibility of this approach by designing and fabricating a prototype all-silicon meta-optic for thermal imaging, which can achieve a high-resolution image of the scene with a FOV of 60 degrees.