News | Aug 6, 2019

US Navy invents non-mechanical laser steering, files for patent, offers to industry

Potential applications include monitoring chemicals, emissions from waste sites, refineries

The patent-pending technology is available to qualified businesses through a license agreement.

Navy photo

A team of scientists at the Naval Research Laboratory has invented a non-mechanical chip-based beam steering technology that can replace mechanical gimbal-style laser scanners.

The Navy’s application for a U.S. patent on the invention was published on July 4, 2019. (Download available below)

The document, available below, states that the laser technology is now available to qualified businesses for commercialization via license agreement. TechLink is facilitating for interested parties.

Known as a steerable electro-evanescent optical refractor, or SEEOR, it takes laser light in the mid-wavelength infrared (MWIR) as an input and steers the beam in two dimensions at the output without the need for mechanical devices — demonstrating improved steering capability and higher scan speed rates than conventional methods.

“Given the low size, weight and power consumption and continuous steering capability, this technology represents a promising path forward for MWIR beam-steering technologies, Jesse Frantz, a research physicist at the lab’s Optical Sciences Division, said in a news release.

“Mapping in the MWIR spectral range demonstrates useful potential in a variety of applications, such as chemical sensing and monitoring emissions from waste sites, refineries, and other industrial facilities.”

News Article Image of US Navy invents non-mechanical laser steering, files for patent, offers to industry

To date, beam steering has typically relied on mechanical devices, such as gimbal-mounted mirrors or rotating Risley prisms, which have inherent issues, including large size, weight, and power (SWaP) requirements, slow scan rates, high repair and replacement costs, and short lifetimes before mechanical failure. Steerable electro-evanescent optical refractor (SEEOR) chips take laser light in the mid-wavelength infrared (MWIR) as an input and steers the beam at the output in two dimensions without the need for mechanical devices. SEEORs are meant to replace traditional mechanical beam steerers with much smaller, lighter, faster devices that use miniscule amounts of electrical power and have long lifetimes because they have no moving parts.

Jason Myers/NRL

The SEEOR is based on an optical waveguide – a structure that confines light in a set of thin layers with a total thickness of less than a tenth that of a human hair.

Laser light enters through one facet and moves into the core of the waveguide. Once in the waveguide, a portion of the light is located in a liquid crystal (LC) layer on top of the core.

A voltage applied to the LC through a series of patterned electrodes changes the refractive index (in effect, the speed of light within the material), in portions of the waveguide, making the waveguide act as a variable prism. Careful design of the waveguides and electrodes allow this refractive index change to be translated to high speed and continuous steering in two dimensions.

SEEORs were originally developed to manipulate shortwave infrared (SWIR) light – the same part of the spectrum used for telecommunications – and have found applications in guidance systems for self-driving cars.

“Making a SEEOR that works in the MWIR was a major challenge,” Frantz said. “Most common optical materials do not transmit MWIR light or are incompatible with the waveguide architecture, so developing these devices required a tour de force of materials engineering.”

To accomplish this, the NRL researchers designed new waveguide structures and LCs that are transparent in the MWIR, new ways to pattern these materials, and new ways to induce alignment in the LCs without absorbing too much light..

The resulting SEEORs were able to steer MWIR light through an angular range of 14°×0.6°.

Dr. Austin Leach, associate director of TechLink, specializes in connecting businesses to NRL’s portfolio of technologies.

“The lab is still working on increasing the range of the angles and spectrum that the chips can use,” said Leach. “But we’re working to introduce businesses to the lab and the technology transfer process.”


Businesses interested in evaluating and licensing the technology can contact Austin Leach at austin.leach@montana.edu or by telephone at 406-994-7707.