This new MIT technology brings us one step closer to ‘Star Wars’ style holograms

technology

The device also has practical applications, such as improving sensors in self-driving cars and brain scanners.

You may remember the iconic scene at the beginning of 1977’s Star Wars: A New Hope, where a little bluish hologram of Princess Leia begs Obi-Wan Kenobi for help.

Sci-fi film series have forever shaped society’s vision of what holograms might look like, but 45 years after the films premiered, humanity still lacks such technology.

The problem, according to MIT researchers, is that generating free-standing 3D holograms requires very precise and fast control of light, beyond the capabilities of existing technologies.

For the past four years, an international group of researchers led by a team at MIT has been trying to overcome this hurdle, says a university news release.

It was announced Monday that a research team has created a programmable wireless device that can control light orders of magnitude faster than commercially available devices.

The device, called a spatial light modulator (SLM), will not only create holograms, but will also have practical applications, the release said.

One use is to create sensors for self-driving cars that operate a million times faster than current sensors. Another possibility is to speed up the brain scanner so that it can create higher-resolution images, the release said.

“We focus on an age-old and recurring research theme: the control of light. It’s a big step towards the ultimate goal of control.

SLMs manipulate light by controlling how light is projected into space. Similar to overhead projectors and computer screens, SLMs alter light rays by focusing them in one direction or refracting them in many places to form an image.

Inside MIT’s new SLM, an array of densely packed photonic crystal microcavities act as light modulators, the release says. These must be very small, since the wavelength of the light beam is only a few nanometers.

When light enters a cavity, it is held for about 1 nanosecond and bounces over 100,000 times before leaving space. A nanosecond is only a billionth of a second, but it’s long enough for a device to manipulate light.

By changing the reflectivity of the cavity, the device controls how light escapes, which determines what we see, the release says.

The team created a micro LED display to control the SLM, the release said. Since the LED pixels have corresponding photonic crystals, when the laser hits the microcavity, the cavity will react differently to the laser based on the light from the LED.

Using LEDs to control devices means that the array is not only programmable and reconfigurable, but completely wireless.

The device is so complex that it took years to figure out how to make it on scales of various sizes. So we were able to mass produce the device, but microscopic deviations occurred during the manufacturing process.

Given how small the cavity is, these slight deviations can lead to large variations in performance, according to the release.

Ultimately, the researchers partnered with the Air Force Research Laboratory to create a high-precision, mass-manufactured process for stamping billions of microcavities onto 12-inch silicon wafers, with control methods for quality assurance. Did.

“We have shown that a very uniform foundry process can produce world-class devices after changing some characteristics of the manufacturing process. It’s about figuring out how to make it manufacturable,” Panuski said in the release.

Now that the manufacturing process is complete, the researchers are working on making larger devices, the release said.