Researchers have developed new 3-D printed microlenses with adjustable refractive indices ̵
The study, led by researchers at the University of Illinois Urbana-Champaign Paul Brown and Linford Goddard, was the first to demonstrate the ability to adjust the direction in which light bends and travels through a lens to the nearest micrometer.
The results of the study are published in the journal Light: science and application.
“Having the ability to produce optics with different shapes and optical parameters offers a solution to common problems in optics,” said Brown, who is a professor of materials science and engineering. “For example, in image applications, focusing on a specific object often results in blurred edges. Or in data transfer applications, higher speeds are desired without sacrificing computer chip space. Our new lens manufacturing technology solves these problems in one integrated device. “
As a demonstration, the team made three lenses: a flat lens; the world’s first Luneburg lens with visible light – previously impossible to produce spherical lens with unique focusing properties; and 3-D waveguides that can allow massive data routing capabilities.
“A standard lens has a single refractive index and therefore only one path through which light can pass through the lens,” said Godard, a professor of electrical engineering and computer engineering. “By controlling the internal refractive index and the shape of the lens during production, we have two independent ways to bend the light inside a lens.”
In the lab, the team uses a process called direct laser writing to create the lenses. The laser hardens liquid polymers and forms small geometric optical structures up to 100 times smaller than human hair. Direct laser writing has been used in the past to create other microlenses that had only one refractive index, the researchers said.
“We overcame the limitations of the refractive index by printing inside nanoporous scaffolding support material,” Brown said. “The scaffolding locks the printed micro-optics in place, allowing the production of a three-dimensional system with suspended components.”
The researchers theorize that this refractive index control is a result of the polymer determination process. “The amount of polymer that enters the pores is controlled by the laser intensity and exposure conditions,” Brown said. “Until the optical properties of the polymer itself change, the overall refractive index of the material is monitored as a function of laser exposure.”
Team members said they expect their method to significantly impact the production of complex optical components and imaging systems and will be useful for the advancement of personal computers.
“A great example of the application of this development would be its impact on data transfer within a personal computer,” Goddard said. “Current computers use electrical connections to transmit data. However, data can be sent at a significantly higher speed using an optical waveguide, as different colors of light can be used to send data in parallel. The main challenge is that conventional waveguides can only be made in one plane and so a limited number of points on the chip can be connected. By creating three-dimensional waveguides, we can drastically improve data routing, transfer speed and energy efficiency. ”
3-D printed glass improves the optical flexibility of the design
Christian R. Ocier et al, Direct laser writing of objective lenses and waveguides with a gradient index, Light: Science and Applications (2020). DOI: 10.1038 / s41377-020-00431-3
Provided by the University of Illinois at Urbana-Champaign
Quote: Researchers face the challenges of optics and data transfer with 3D printed lenses (2020, December 3), retrieved on December 4, 2020 from https://phys.org/news/2020-12-optics-data -transfer-3d-printed-lens .html
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