A strong laser is seen illuminating a material in a low-temperature chamber. The laser is being used to change the material’s degree of transparency.
Credit: Caltech/David Hsieh Laboratory
Imagine windows that can easily transform into mirrors, or super high-speed computers that run not on electrons but light. These are just some of the potential applications that could emerge from optical engineering, the practice of using lasers to rapidly and temporarily change the properties of materials.
“These tools could let you transform the electronic properties of materials at the flick of a light switch,” says Caltech Professor of Physics David Hsieh. “But the technologies have been limited by the problem of the lasers creating too much heat in the materials.”
In a new study in Nature, Hsieh and his team, including lead author and graduate student Junyi Shan, report success at using lasers to dramatically sculpt the properties of materials without the production of any excess damaging heat.
“The lasers required for these experiments are very powerful, so it’s hard to not heat up and damage the materials,” says Shan. “On the one hand, we want the material to be subjected to very intense laser light. On the other hand, we don’t want the material to absorb any of that light at all.”
The team found a “sweet spot” to get around this, Shan says, where the frequency of the laser is fine-tuned in such a way to markedly change the material’s properties without imparting any unwanted heat.
The scientists also say they found an ideal material to demonstrate this method. The material, a semiconductor called manganese phosphorus trisulphide, naturally absorbs only a small amount of light over a broad range of infrared frequencies. For their experiments, Hsieh, Shan, and colleagues used intense infrared laser pulses, each lasting about 10-13 seconds, to rapidly change the energy of electrons inside the material. As a result, the material shifted from a highly opaque state to a highly transparent one for certain colors of light.
Even more critical, the researchers say, is that the process is reversible. When the laser turns off, the material instantly goes back to its original state completely unscathed. This would not be possible if the material had absorbed the laser light and heated up because it would take a long time for the material to dissipate the heat. The heat-free manipulation used in the new process is known as “coherent optical engineering.”
The method works because the light alters the differences between the energy levels of electrons in the semiconductor (called band gaps) without kicking the electrons themselves into different energy levels, which is what generates heat.
“It’s as if you have a boat, and then a big wave comes along and vigorously rocks the boat up and down without causing any of the passengers to fall down,” explains Hsieh. “Our laser is vigorously rocking the energy levels of the material, and that alters the materials’ properties, but the electrons stay put.”
Researchers have previously theorized how this method would work. For example, in the 1960s, Caltech alumnus Jon H. Shirley (PhD ’63), put forth mathematical ideas about how to solve for electron-energy levels in a material in the presence of light. Building on this work, Hsieh’s Caltech team collaborated with theorists Mengxing Ye and Leon Balents from UC Santa Barbara to calculate the expected effects of laser illumination in manganese phosphorus trisulphide. The theory matched the experiments with “remarkable” accuracy, says Hsieh.
The findings, Hsieh says, mean that other researchers can now potentially use light to artificially create materials, such as exotic quantum magnets, which would have been otherwise difficult or even impossible to create naturally.
“In principle, this method can change optical, magnetic, and many other properties of materials,” says Shan. “This is an alternative way of doing materials science. Rather than making new materials to realize different properties, we can take just one material and ultimately give it a broad range of useful properties.”
Original Article: Transforming Materials with Light
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
- Physics-based modeling to data-driven learning? The paradigm shift in optical metrology
optical engineering, computer vision, and computational imaging. Recently, deep learning (DL), a subfield of machine learning, has been gaining extensive attention for its extensive applications ...
- Long-term in vivo imaging technique developed to better understand and treat spinal cord injury
Qu, who is an expert of optical engineering and science with extensive experience in in vivo linear and nonlinear optical spectroscopy and imaging of biological tissues from a variety of animal ...
- Diffractive Optical Elements Market To Surpass Valuation Of US$ 1 Bn By 2031
Laser Optical Engineering Ltd, Laserglow Technologies, LightTrans GmbH, SILIOS Technologies., Sintec Optronics Pte Ltd, SÜSS MicroTec SE, Nil Technology, and AGC Group. A baby-faced 20-year-old ...
- Innovative imaging technique may pave the way for better understanding and treatment of spinal cord injury
Prof. Qu Jianan, Professor of Department of Electrical & Computer Engineering Prof. Qu, is an expert of optical engineering and science with extensive experience in in vivo linear and nonlinear ...
- Optical Engineering Services
The optical engineering services provided by Shanghai Optics is our way of making more than 55 years of experience in optical engineering, opto mechanical engineering, product development and design ...
Go deeper with Google Headlines on:
Go deeper with Bing News on:
Coherent optical engineering
- Optical Imaging Market Report With Executive Summary, Size, Analysis And Forecast To 2022-2031
The key players profiled in the report are Michelson Diagnostics, Heidelberg Engineering GmBH ... will cover the technological aspects of Optical Coherence Tomography (OCT), Photo - Acoustic ...
- Small microring array enables large complex-valued matrix multiplication
Matrix computing has become one of the most widely used and indispensable information processing tools in science and engineering ... that traditional non-coherent optical computing schemes ...
- OCT-A used in long Covid research
Dr Bettina Hohberger, from the Eye Clinic at the Friedrich Alexander University in Erlangen, Germany, has won the Heidelberg Engineering Xtreme Research Award for her diagnostic insights into long ...
- Post-Doctoral Associate in Division of Engineering, Bioengineering
Applicants with strong backgrounds in Engineering, Optics, Physics and other relevant disciplines are sought to join leading efforts in the development and application of new optical technologies such ...
- Coherent Transmission Market Continues to Gain a Stronghold Amidst into 2022 | By -Cisco, Infinera Corporation, Ciena Corporation
ADVA Optical Networking, Telefonaktiebolaget LM Ericsson, NEC Corporation, Carl Zeiss Meditec, Vision Engineering Ltd, & Others Receive the Sample Report of Coherent Transmission Market 2022 to ...