An array of nine spatial light modulators immersed in the organic active layer. Image: Capasso Lab/Harvard SEAS.
An array of nine spatial light modulators immersed in the organic active layer. Image: Capasso Lab/Harvard SEAS.

Spatial light modulators are common optical components found in everything from home theater projectors to cutting-edge laser imaging to optical computing. These components can control various aspects of light, such as intensity and phase, pixel by pixel. Most spatial light modulators today rely on mechanical moving parts to achieve this control but that approach results in bulky and slow optical devices.

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), in collaboration with a team from Washington University, have developed a simple spatial light modulator made from gold electrodes covered in a thin film of electro-optical material that changes its optical properties in response to electric signals.

This represents a first step towards more compact, high-speed and precise spatial light modulators that could one day be used for everything from imaging to virtual reality to quantum communications to sensing. The researchers report their advance in a paper in Nature Communications.

“This simple spatial light modulator is a bridge between the realms of optics and electronics,” said Cristina Benea-Chelmus, a postdoctoral fellow at Harvard SEAS and first author of the paper. “When you interface optics with electronics, you can use the entire backbone of electronics that has been developed to open up new functionalities in optics.”

The researchers used an electro-optic material designed by chemists Delwin Elder and Larry Dalton at the University of Washington. Applying an electric signal to this material causes its refractive index to change. By dividing the material into pixels, the researchers could control the intensity of light in each pixel separately using interlocking electrodes.

With only a small amount of power, the resulting device can dramatically change the intensity of light at each pixel and can efficiently modulate light across the visible spectrum. The researchers used these new spatial light modulators for image projection and remote sensing by single-pixel imaging.

“We consider our work to mark the beginning of an up-and-coming field of hybrid organic-nanostructured electro-optics with broad applications in imaging, remote control, environmental monitoring, adaptive optics and laser ranging,” said Federico Capasso, professor of applied physics and a senior research fellow in electrical engineering at Harvard SEAS, who is senior author of the paper.

This story is adapted from material from Harvard SEAS, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.