Manufacturing Bits: Feb. 2

Do-it-yourself optoelectronics
The University of Illinois at Urbana-Champaign has developed a technology to make optical components on a do-it-yourself basis.

To make a component, researchers have devised what they call plasmon-assisted etching. The process makes use of a nanostructured template, which can be used to create optical components.

The template is a 2D array of gold pillar-supported bowtie nanoantennas. In the flow, the template is submerged in water. A laser light scans the template.

The gold layer of the nanoantennas then undergoes a thermal expansion effect. The force provided by thermal expansion allows the gold layer to break away from a substrate, thereby etching the metal. “Our method uses the intuitive design aspects of diffractive optics by way of simple surface modification, and the electric-field enhancement properties of metal nanoantennas, which are typically the building blocks of metasurfaces,” said Hao Chen, a researcher at University of Illinois at Urbana-Champaign, on the university’s Web site.

Image of a Fresnel zone plate (left). A 2D array of pillar-supported bowtie nanoantennas (right). (Source: University of Illinois at Urbana-Champaign)

In the lab, researchers fabricated a flat focusing lens, sometimes called a Fresnel zone plate. In addition, researchers also made a diffraction grating and a holographic converter.

“Our method brings us closer to making do-it-yourself optics a reality by greatly simplifying the design iteration steps,” said Kimani Toussaint, an associate professor of mechanical science and engineering at University of Illinois at Urbana-Champaign. “The process incorporates a nanostructured template that can be used to create many different types of optical components without the need to go into a cleanroom to make a new template each time a new optical component is needed.”

Making photonic thermometers
The National Institute of Standards and Technology (NIST) has found a new way to package and test its next-generation photonic thermometers.

For some time, NIST has been developing photonic thermometers, which are chip-based systems that measure temperature using light. They are resistant to electromagnetic interference and are self-calibrating. In the future, photonic thermometers could be buried into walls or sent into space. They could be used for chemical, pressure and humidity detection.

Now, to speed up the commercialization of its photonic thermometers, NIST has devised a system that automatically tests and packages these units at high speeds.

The test system attaches an array of optical fibers to a photonic chip. The fibers consist of tiny temperature-measurement devices. Then, the system automatically moves the chip beneath the fiber array. At that point, the test station “measures the output of light flowing from a laser through the fibers into the on-chip integrated sensors and then flowing out through another set of fibers into a photodetector,” according to NIST.

Automated testing-and-packaging station (Source: NIST)

The system also characterizes the quality of the connection. If it passes, then a mini syringe filled with special epoxy is bonded to the fibers. “With our new setup we are no longer delayed with tedious and time-consuming fiber-to-chip bonding,” said Nikolai Klimov, a scientist in the Physical Measurement Laboratory (PML) at NIST, on the agency’s Web site. “Our developed packaging system is not only consistent with the best photonics industry manufacturing standards, but also opens doors for more applications and fundamental research, creating a bridge between industry and academia.”

Zeeshan Ahmed, who leads the photonic thermometry team, added: “This tool is important because to commercialize these sensors, we need to present them in a form factor or shape that people are comfortable with. When people think of a thermometer, they think of a cylinder with a wire coming off of it. They don’t think of a chip that just sits on a table.”

Manufacturing awards
Separately, NIST opened a competition to award new cooperative funding agreements for its Hollings Manufacturing Extension Partnership (MEP) centers in the United States and Puerto Rico.

The MEP centers help small and mid-sized U.S. manufacturers create and retain jobs, increase profits and save time and money. The current competition will fund awards for centers in Alabama, Arkansas, California, Georgia, Louisiana, Massachusetts, Missouri, Montana, Ohio, Pennsylvania, Puerto Rico, Utah and Vermont.

The awards provide half of each center’s first-year operating funds, which the centers must match with funding from nonfederal sources. MEP anticipates awarding a total of nearly $39 million for up to 13 centers in these locations.