Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Caltech Researchers Create Light-Bending Silicon Chip: Bending the Light with a Tiny Chip

An image of Hajimiri's light-bending silicon chip.
Credit: Ali Hajimiri/Caltech
An image of Hajimiri's light-bending silicon chip.

Credit: Ali Hajimiri/Caltech

Abstract:
Imagine that you are in a meeting with coworkers or at a gathering of friends. You pull out your cell phone to show a presentation or a video on YouTube. But you don't use the tiny screen; your phone projects a bright, clear image onto a wall or a big screen. Such a technology may be on its way, thanks to a new light-bending silicon chip developed by researchers at Caltech.



The letters "C," "I," and "T" projected using Hajimiri's optical phased array chip. The images shown were projected in infrared light. Credit: Ali Hajimiri/Caltech

Caltech Researchers Create Light-Bending Silicon Chip: Bending the Light with a Tiny Chip

Pasadena, CA | Posted on March 10th, 2014

The chip was developed by Ali Hajimiri, Thomas G. Myers Professor of Electrical Engineering, and researchers in his laboratory. The results were presented at the Optical Fiber Communication (OFC) conference in San Francisco on March 10.

Traditional projectors—like those used to project a film or classroom lecture notes—pass a beam of light through a tiny image, using lenses to map each point of the small picture to corresponding, yet expanded, points on a large screen. The Caltech chip eliminates the need for bulky and expensive lenses and bulbs and instead uses a so-called integrated optical phased array (OPA) to project the image electronically with only a single laser diode as light source and no mechanically moving parts.

Hajimiri and his colleagues were able to bypass traditional optics by manipulating the coherence of light—a property that allows the researchers to "bend" the light waves on the surface of the chip without lenses or the use of any mechanical movement. If two waves are coherent in the direction of propagation—meaning that the peaks and troughs of one wave are exactly aligned with those of the second wave—the waves combine, resulting in one wave, a beam with twice the amplitude and four times the energy as the initial wave, moving in the direction of the coherent waves.

"By changing the relative timing of the waves, you can change the direction of the light beam," says Hajimiri. For example, if 10 people kneeling in line by a swimming pool slap the water at the exact same instant, they will make one big wave that travels directly away from them. But if the 10 separate slaps are staggered—each person hitting the water a half a second after the last—there will still be one big, combined wave, but with the wave bending to travel at an angle, he says.

Using a series of pipes for the light—called phase shifters—the OPA chip similarly slows down or speeds up the timing of the waves, thus controlling the direction of the light beam. To form an image, electronic data from a computer are converted into multiple electrical currents; by applying stronger or weaker currents to the light within the phase shifter, the number of electrons within each light path changes—which, in turn, changes the timing of the light wave in that path. The timed light waves are then delivered to tiny array elements within a grid on the chip. The light is then projected from each array in the grid, the individual array beams combining coherently in the air to form a single light beam and a spot on the screen.

As the electronic signal rapidly steers the beam left, right, up, and down, the light acts as a very fast pen, drawing an image made of light on the projection surface. Because the direction of the light beam is controlled electronically—not mechanically—it can create a sort of line very quickly. Since the light draws many times per second, the eye sees the process as a single image instead of a moving light beam, says Hajimiri.

"The new thing about our work is really that we can do this on a tiny, one-millimeter-square silicon chip, and the fact that we can do it very rapidly—rapidly enough to form images, since we phase-shift electronically in two dimensions," says Behrooz Abiri, a graduate student in Hajimiri's group and a coauthor on the paper. So far, the images Hajimiri and his team can project with the current version of the chip are somewhat simple—a triangle, a smiley face, or single letters, for example. However, the researchers are currently experimenting with larger chips that include more light-delivering array elements that—like using a larger lens on a camera—can improve the resolution and increase the complexity of the projected images.

In their recent experiments, Hajimiri and his colleagues have used the silicon chip to project images in infrared light, but additional work with different types of semiconductors will also allow the researchers to expand the tiny projector's capabilities into the visible spectrum. "Right now we are using silicon technology, which works better with infrared light. If you want to project visible light, you can take the exact same architecture and do it in what's called compound semiconductor III-V technology," says Firooz Aflatouni, another coauthor on the paper, who in January finished his two-year postdoctoral appointment at Caltech and joined the University of Pennsylvania as an assistant professor. "Silicon is good because it can be easily integrated into electronics, but these other compound semiconductors could be used to do the same thing."

"In the future, this can be incorporated into a phone, and since there is no need for a lens, you can have a phone that acts as a projector all by itself," Hajimiri says. However, although the chip could easily be incorporated into a cell phone, he points out that a tiny projection device can have many applications—including light-based radar systems (called "LIDAR"), which are used in positioning, robotics, geographical measurements, and mapmaking. Such equipment already exists, but current LIDAR technology requires complex, bulky, and expensive equipment—equipment that could be streamlined and simplified to a single chip at a much lower cost.

"But I don't want to limit the device to just a few purposes. The beauty of this thing is that these chips are small and can be made at a very low cost—and this opens up lots of interesting possibilities," he says.

These results were described in a presentation titled "Electronic Two-Dimensional Beam Steering for Integrated Optical Phased Arrays." Along with Hajimiri, Abiri, and Aflatouni, Caltech senior Angad Rekhi is also a coauthor on this paper. The work was funded by grants from the Caltech Innovation Initiative, and the Information Science and Technology initiative at Caltech.

# # #

Written by Jessica Stoller-Conrad

####

For more information, please click here

Contacts:
Brian Bell
(626) 395-5832

Copyright © Caltech

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Nanoparticles Used to Improve Quality of Bone Cement September 29th, 2014

Videos/Movies

Smallest possible diamonds form ultra-thin nanothreads: Diamond nanothreads are likely to have extraordinary properties, including strength and stiffness greater than that of today's strongest nanotubes and polymers September 22nd, 2014

Next-Gen Luxury RV From Global Caravan Technologies Will Offer MagicView Roof and Windshield Using SPD-SmartGlass Technology From Research Frontiers: Recreational Vehicle Manufacturer Global Caravan Technologies (GCT) Features 28 Square Feet of MagicView™ SPD-SmartGlass September 17th, 2014

Scientists refine formula for nanotube types: Rice University theorists determine factors that give tubes their chiral angles September 17th, 2014

RMIT delivers $30m boost to micro and nano-tech August 26th, 2014

Ethics

PETA science consortium experts to present at international nanotechology workshop: PETA International Science Consortium, Ltd., Is a Sponsor of Nano Risk Analysis II September 12th, 2014

PETA science consortium to present hazard testing strategy at nanotoxicology meeting: High tech field ripe for use of sophisticated non-animal testing strategies April 22nd, 2014

Scientists disagree on responsible research April 8th, 2014

Building a Better Future — Lessons from 3 Months of Lifeboat Foundation Expert Interviews September 1st, 2013

Discoveries

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Nanoparticles Used to Improve Quality of Bone Cement September 29th, 2014

Announcements

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Nanoparticles Used to Improve Quality of Bone Cement September 29th, 2014

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals

New Topical Hemostatic Agent: Neutral Self-Assembling Peptide Hydrogel September 30th, 2014

Chemical interactions between silver nanoparticles and thiols: A comparison of mercaptohexanol again September 30th, 2014

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Nanoparticles Used to Improve Quality of Bone Cement September 29th, 2014

Events/Classes

Oxford Instruments launches 3rd annual Indian nanotechnology seminars in Kolkata and Delhi - sharing expertise with Nanotechnology researchers in India September 25th, 2014

Grenoble Hosting SEMICON Europa Oct. 7-9, First Time Event Held in France: Leti’s 90-square-meter Booth Will Feature Portable Showroom To Demonstrate New Technology Innovations September 24th, 2014

Contributing to the spirit of the IYCR 2014 September 24th, 2014

BSA Distinguished Lecture Tuesday, 10/14: 'LCLS: A Stunning New View Through X-ray Laser Eyes' September 23rd, 2014

Grants/Awards/Scholarships/Gifts/Contests/Honors/Records

A Heartbeat Away? Hybrid "Patch" Could Replace Transplants: TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch September 30th, 2014

Teijin Aramid’s carbon nanotube fibers awarded with Paul Schlack prize: New generation super fibers bring wave of innovations to fiber market September 25th, 2014

New chip promising for tumor-targeting research September 22nd, 2014

SouthWest NanoTechnologies (SWeNT) Receives NIST Small Business Innovation Research (SBIR) Phase 1 Award to Produce Greater than 99% Semiconducting Single-Wall Carbon Nanotubes September 19th, 2014

Photonics/Optics/Lasers

'Pixel' engineered electronics have growth potential: Rice, Oak Ridge, Vanderbilt, Penn scientists lead creation of atom-scale semiconducting composites September 29th, 2014

Southampton scientists grow a new challenger to graphene September 23rd, 2014

Engineers show light can play seesaw at the nanoscale: Discovery is another step toward faster and more energy-efficient optical devices for computation and communication September 22nd, 2014

Twisted graphene chills out: When two sheets of graphene are stacked in a special way, it is possible to cool down the graphene with a laser instead of heating it up, University of Manchester researchers have shown September 22nd, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE