Researchers highlight the latest nanostructured components integrated on image sensor chips that are most likely to make the biggest impact in multimodal imaging and detailed a promising approach to detect multiple-band spectra by fabricating an on-chip spectrometer.

Image sensors measure light intensity, but angle, spectrum, and other aspects of light must also be extracted to significantly advance machine vision. [1]

Figure 1. Improving image sensors for machine vision

Figure 1 shows “Image sensors will gradually undergo a transition to become the ideal artificial eyes of machines,” co-author Yurui Qu, from the University of Wisconsin-Madison, said. “An evolution leveraging the remarkable achievement of existing imaging sensors is likely to generate more immediate impacts.”

Image sensors, which converts light into electrical signals, are composed of millions of pixels on a single chip. The challenge is how to combine and miniaturize multifunctional components as part of the sensor.

In their own work, the researchers detailed a promising approach to detect multiple-band spectra by fabricating an on-chip spectrometer. They deposited photonic crystal filters made up of silicondirectly on top of the pixels to create complex interactions between incident light and the sensor. [2].

The researchers built a component that detects angular information to measure depth and construct 3D shapes at subcellular scales. Their work was inspired by directional hearing sensors found in animals, like geckos, whose heads are too small to determine where sound is coming from in the same way humans and other animals can. Instead, they use coupled eardrums to measure the direction of sound within a size that is orders of magnitude smaller than the corresponding acoustic wavelength.

Similarly, pairs of silicon nanowires were constructed as resonators to support optical resonance. The optical energy stored in two resonators is sensitive to the incident angle. The wire closest to the light sends the strongest current. By comparing the strongest and weakest currents from both wires, the angle of the incoming light waves can be determined. [3]

References:

1. https://statnano.com/news/71168/Improving-Image-Sensors-for-Machine-Vision
2. https://autotech.news/improving-image-sensors-for-machine-vision/
3. https://www.sciencedaily.com/releases/2022/07/220726132521.htm

Cite this article:

Thanusri swetha J (2022), Improving image sensors for machine vision, Anatechmaz, pp. 383