SMART researchers create the world’s smallest LED and holographic microscope that converts existing mobile phone cameras into high-resolution microscopes.
Researchers from the Interdisciplinary Research Groups (IRG) Disruptive & Sustainable Technologies for Agricultural Precision (DiSTAP) and Critical Analytics for Manufacturing Personalization-Medicine (CAMP) of the Singapore-MIT Alliance for Research and Technology (SMART), the MIT research company in Singapore have developed the world’s smallest LED (Light Eemitting Diode) that enables the conversion of existing mobile phone cameras into high-resolution microscopes.
Smaller than the wavelength of light, the new LED has been used to build the world’s smallest holographic microscope, paving the way for existing cameras in everyday devices such as cell phones to be converted into microscopes via only modifications to the silicon chip and software. This technology also represents a significant improvement in the reduction of research costs for indoor farmers and sustainable agriculture.
This breakthrough is due to the development by researchers of a neural algorithm that can reconstruct the objects measured by the holographic microscope, thus enabling a better analysis of visible objects such as cells and bacteria. Bacteria without the need for large traditional microscopes or other optical equipment. This discovery also paves the way for great progress in photonics – the construction of a powerful emitter that is smaller than a micrometer, which has been far from the field.
The light in most photonic chips comes from external sources, which leads to low power efficiency and prevents the end of these chips. To solve this problem, researchers have developed on-chip emitters using different materials such as rare earth doped glass, Ge-on-Si, and various III-V combined materials. Although manufacturers based on these materials have shown promising device performance, integrating their manufacturing processes into standard CMOS (meta-oxide-semiconductor) processors remains elusive. hands. Although the silialon (from) has been shown as an experimenter for the experts and the basket is not restricted to the available tools to know which one send it to Cmos.
In tracking communication speech lists recently, researchers say that the CMOM and CMOS declares that which shows that that makes technology makes it great. In a similar event, SMART researchers also revealed their architecture of an untrained deep neural network architecture that can reconstruct images from a holographic microscope in a paper titled “Simultaneous Spectral Retrieval and Micro-LED Holography CMOS and untrained deep neural networks”. It was recently published in the journal Optica.
The new lamp developed by SMART researchers is a room-temperature CMOS integrated sub-wavelength scale LED with high spatial intensity (102±48mW/cm2) and minimum emission area (0 .09±0.04 μm2) between all known Si emitters in the scientific literature. To demonstrate practical applications, the researchers integrated this LED into a linear, centimeter-scale, all-silicon holographic microscope, without requiring a hole or pinhole, which is an important part of the known field. holeless holography.
An obstacle often encountered in gapless holography is the mathematical reconstruction of the image. Traditional reconstruction methods require detailed knowledge of the experimental setup for accurate reconstruction and are sensitive to difficult-to-control variables such as optical distortion, the presence of noise, and the twin image problem.
The research team also developed a deep neural network architecture to improve the quality of image reconstruction. This new untrained deep neural network incorporates full variation regularization for increased contrast and takes into account the wide spectral bandwidth of the source. Unlike traditional computational reconstruction methods that require training data, this neural network eliminates the need for training by incorporating physical models into the algorithm.
In addition to holographic image reconstruction, the neutral grating also provides blind recovery of the spectrum of the source from the same strong energy system, which indicates the transition from all the learning processes that are managed and first. The untrained neural network presented in this study allows researchers to use new light sources without prior knowledge of the spectrum or beam profile, such as new and the least known Si LED described above, which is produced from unmodified, complete commercial large CMOS microelectronics.
The researchers think that the synergistic combination of CMOS micro-LEDs and neural networks can be used in other imaging devices, such as compact microscopes for cell tracking or biological tissue modeling. like a living plant. This work also demonstrates the power of next-generation imaging systems on-chip. Already, online holographic microscopes have been used for a variety of applications, including particle tracking, environmental monitoring, imaging of biological samples, and metrology. Other applications include networking these LED lights with CMOS to create integrated lighting for future complex systems.
Iksung Kang, the lead author of the Optica paper and a research assistant at MIT during this study, said, “Our invention represents a proof of concept that can have significant implications for many applications that require micro-LEDs. For example, this LED can be connected in series for the higher light levels required for larger applications.
Additionally, due to the low cost and scalability of CMOS microelectronics systems, this can be done without increasing system complexity, cost, or form factors. This allows us to transform, in a simple way, a mobile phone camera into a holographic microscope of this type. In addition, the control electronics and even the imager are combined in the same chip using the electronics in the system, creating an “all-in-one” micro-LED which can be changed for the field.
“In addition to its great potential in gapless holography, our new LED has many other possible applications. Because its wavelength is in the smallest acceptance window of living tissue, and its high power, nanoscale emission region, our LED can be suitable for bio-imaging and bio-sensing applications, including near-field microscopy and embedded CMOS devices,” added Rajeev Ram, Principal Investigator at SMART CAMP and DiSTAP, Professor of Electrical Engineering at MIT and co-author of both papers. “Furthermore, it is possible to integrate this LED into on-chip photodetectors, but it may find other applications in on-chip communication, NIR proximity sensing, and on-wafer photonic testing.”
Source: Singapore-MIT Alliance for Research and Technology (SMART)
