NTT Device Technology Lab publishes an OSA Optica paper "Full-color-sorting metalenses for high-sensitivity image sensors" by Masashi Miyata, Naru Nemoto, Kota Shikama, Fumihide Kobayashi, and Toshikazu Hashimoto.
"Image sensors play a critical role in current technologies ranging from smartphones to autonomous vehicles. In these technologies, high-sensitivity image sensors are highly desired because they enable dark-scene/ultra-fast imaging. Unfortunately, a conventional sensor architecture that employs color filters on every pixel fundamentally limits the detected light power per pixel because of the filtering, which has been a long-standing barrier to sensitivity improvement. Here, we demonstrate polarization-insensitive metasurface lenses (metalenses) that sort primary colors on high-density pixels without the use of color filters. The metalenses simultaneously act as pixel-scale color splitters and lenses and are compatible with complementary metal–oxide-semiconductor sensor technology. An image sensor with such metalenses significantly enhances the detected light power, while affording high image quality, incident angle tolerance, and sub-micrometer spatial resolution. The demonstrated architecture opens the way to the development of high-sensitivity color image sensors that exceed current limits while maintaining consistency with state-of-the-art sensor technology."
There have been some interesting metalens designs published so far. This one falls into the waveguide category that features quite long nanopost with high index and modulate phase shift by horizontal dimension. I am curious about the cost of manufacturing such metalens and how is the yield rate if any.
ReplyDeleteIt is fascinating how this works... Are this metalens probably fabricated similar to DTI or MEMS structures? like described here: https://en.wikipedia.org/wiki/Deep_reactive-ion_etching#Bosch_process
Deleteif it is etched the cost should be quite low, similar process steps happen many times for e.g. every image sensor with DTI
Thanks for the reply. I guess you are right. many other papers on metalens mentioned the etch process repeatedly. So I think this may apply to this paper as well.
DeleteThe SiN metasurface structrure seems to be very thick, is there any risk of film peeling during the process.
ReplyDelete