PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Physicist builds useful light source from harmonic generation

Physicist builds useful light source from harmonic generation
2014-06-02
(Press-News.org) MANHATTAN, KANSAS — A Kansas State University physicist's proposal may lead to a new way of creating tabletop light sources in the laboratory.

Cheng Jin, research associate in physics; Chii-Dong Lin, university distinguished professor of physics; and collaborators are developing a way to greatly enhance the generation of high-order harmonics to create powerful small tabletop light sources that are important to science and technology.

The researchers are building theoretical framework and providing experimental guidance in the area of strong-field physics. The work is associated with the physics department's James R. Macdonald Laboratory.

"The ultimate goal of this research is to design any waveforms to control physical processes for different applications," Jin said.

The research appears in a recent Nature Communications article, "Waveforms for optimal sub-keV high-order harmonics with synthesized two- or three-colour laser fields." In the field of atomic, molecular and optical physics, it is rare for such a theoretical paper to be published in a multidisciplinary research journal such as Nature Communications, Jin said.

Other Kansas State University researchers involved include Anh-Thu Le, research associate professor of physics; Hui Wei, doctoral student in physics; and Guoli Wang, visiting scholar in physics and associate professor at Northwest Normal University in China.

High-order harmonic generation is an extreme nonlinear process when intense infrared lasers are focused in a gas medium. When used with the right filters, high-order harmonic generation pulses, which range from extreme ultraviolet to X-ray, can be used for numerous applications in science and technology.

For example, the emitted harmonics can produce isolated attosecond pulses or attosecond pulse trains. An attosecond is one-billionth of a billionth of a second. These attosecond pulses are used to study the dynamics of atoms, molecules and condensed media, and to investigate their evolution at the femtosecond and attosecond timescales. A femtosecond is one-millionth of a billionth of a second.

"High-order harmonic generation has been considered a very promising way to provide the tabletop coherent light sources in the extreme ultraviolet to X-ray regions, but so far is limited by its low intensity," Jin said.

While Jin has extensively studied high-order harmonic generation, the latest publication proposes a method of synthesizing two- or three-color lasers to optimize the intensity of high-order harmonic generation.

"Our method can greatly enhance the harmonic intensity by one to two orders of magnitude without the increase of total laser power," Jin said. "With the emerging intense high-repetition megahertz lasers, this paves a way to make high-order harmonic generation as a useful light in the coming years."

While laser technology of synthesizing two- or three-color lasers already exists, without the guidance of their work it is difficult to locate the laser parameters, such as laser intensities and relative phases between each two colors to form a waveform that optimizes the harmonic intensity in the laboratory by taking trial-and-error methods, Jin said. When these waveform-optimized laser pulses are combined with the emerging high-repetition megahertz lasers, they can generate high harmonics that are much higher than what is available today.

Lin's research group plans future research in the area of strong-field physics.

The group is exploring how to eliminate atto-chirp with a designed waveform, how to achieve the optimized waveform in the gas-filled hollow-core waveguide and how to optimize the waveforms over multiple optical cycles to enhance the intensity of the single harmonic.

"We expect waveform control of intense laser pulses will lead the next wave of research in strong-field physics and the theoretical study carried out in this work is essential for this research to move forward," Jin said.

INFORMATION: Jin's previous research on high-order harmonic generation has been summarized in his book, "Theory of Nonlinear Propagation of High Harmonics Generated in a Gaseous Medium." The book was published by Springer in 2013 and supervised by Lin.

[Attachments] See images for this press release:
Physicist builds useful light source from harmonic generation

ELSE PRESS RELEASES FROM THIS DATE:

CU Denver study shows public health often ignored in transportation policy

2014-06-02
DENVER (June 2, 2014) – A new study from the University of Colorado Denver shows public health issues are often ignored in many transportation projects, especially when major roads are built through lower-income neighborhoods. Air pollution, crime and numerous traffic hazards, the study said, point to a serious and persistent gap between public health and planning. "The public health effects of heavy traffic are broad," said study author Carolyn McAndrews, PhD, assistant professor at the CU Denver College of Architecture and Planning, one of the largest schools of its ...

Surgeons report fewer postoperative blood clots using risk-based preventive measures

2014-06-02
Chicago (June 2, 2014): Surgery patients are much less likely to get a blood clot in the lower extremities or lungs if they receive preventive treatment based on their individual clotting risk, in addition to walking soon after the operation. Results from a surgical quality improvement study, appearing in the June issue of the Journal of the American College of Surgeons, indicate that the odds of this common and potentially life-threatening postoperative complication steadily declined after the implementation of a multicomponent prevention program in a hospital's department ...

Study links evening blue light exposure to increased hunger

2014-06-02
DARIEN, IL – A new study suggests that blue-enriched light exposure immediately before and during the evening meal may increase hunger and alter metabolism. Results show that blue-enriched light exposure, compared with dim light exposure, was associated with an increase in hunger that began 15 minutes after light onset and was still present almost two hours after the meal. Blue light exposure also decreased sleepiness and resulted in higher measures of insulin resistance. "It was very interesting to observe that a single three-hour exposure to blue-enriched light in ...

Astronomers find a new type of planet: The 'mega-Earth'

Astronomers find a new type of planet: The mega-Earth
2014-06-02
Astronomers announced today that they have discovered a new type of planet - a rocky world weighing 17 times as much as Earth. Theorists believed such a world couldn't form because anything so hefty would grab hydrogen gas as it grew and become a Jupiter-like gas giant. This planet, though, is all solids and much bigger than previously discovered "super-Earths," making it a "mega-Earth." "We were very surprised when we realized what we had found," says astronomer Xavier Dumusque of the Harvard-Smithsonian Center for Astrophysics (CfA), who led the data analysis and made ...

'Neapolitan' exoplanets come in three flavors

Neapolitan exoplanets come in three flavors
2014-06-02
The planets of our solar system come in two basic flavors, like vanilla and chocolate ice cream. We have small, rocky terrestrials like Earth and Mars, and large gas giants like Neptune and Jupiter. We're missing the astronomical equivalent of strawberry ice cream - planets between about one and four times the size of Earth. NASA's Kepler mission has discovered that these types of planets are very common around other stars. New research following up on the Kepler discoveries shows that alien worlds, or exoplanets, can be divided into three groups - terrestrials, gas giants, ...

Harsh space weather may doom potential life on red-dwarf planets

Harsh space weather may doom potential life on red-dwarf planets
2014-06-02
Life in the universe might be even rarer than we thought. Recently, astronomers looking for potentially habitable worlds have targeted red dwarf stars because they are the most common type of star, comprising 80 percent of the stars in the universe. But a new study shows that harsh space weather might strip the atmosphere of any rocky planet orbiting in a red dwarf's habitable zone. "A red-dwarf planet faces an extreme space environment, in addition to other stresses like tidal locking," says Ofer Cohen of the Harvard-Smithsonian Center for Astrophysics (CfA). Cohen ...

Because you can't eat just one: Star will swallow two planets

Because you cant eat just one: Star will swallow two planets
2014-06-02
Two worlds orbiting a distant star are about to become a snack of cosmic proportions. Astronomers announced today that the planets Kepler-56b and Kepler-56c will be swallowed by their star in a short time by astronomical standards. Their ends will come in 130 million and 155 million years, respectively. "As far as we know, this is the first time two known exoplanets in a single system have a predicted 'time of death,'" says lead author Gongjie Li of the Harvard-Smithsonian Center for Astrophysics (CfA). She presented her research today in a press conference at a meeting ...

Long-term results encouraging for combination immunotherapy for advanced melanoma

2014-06-02
New Haven, CT — The first long-term follow-up results from a phase 1b immunotherapy trial combining drugs for advanced melanoma patients has shown encouraging results — long-lasting with high survival rates — researchers report. First author Mario Sznol, M.D., professor of medical oncology at Yale Cancer Center, is presenting the updated data at the 2014 annual conference of the American Society of Clinical Oncology (ASCO) in Chicago. Sznol, clinical research leader of the melanoma research program at Yale Cancer Center, was the senior author on the original study of ...

Does your stomach bacteria protect you from obesity?

2014-06-02
The germ Helicobacter pylori is the cause of most stomach ulcers, but new research in Alimentary Pharmacology & Therapeutics suggests that treating the bacteria is linked to weight gain. It is estimated that 50% of the global population may be infected with H. pylori; however, only 20% of infected people experience symptoms. New evidence suggests that patients treated for the infection developed significant weight gain compared to subjects with untreated H. pylori colonization. By reviewing data taken from forty-nine studies with data from ten European countries, Japan, ...

Britain's urban rivers cleanest in 20 years

2014-06-02
Scientists from Cardiff University have found that Britain's urban rivers are the cleanest they've been in over two decades. The 21-year study of over 2300 rivers measured the presence of clean-river invertebrates - a yardstick for river health – which during the days of heavy industry and poor sewage treatment had declined considerably, but now appear to be making a comeback. Although climate change has warmed British rivers by around 1-2 degrees over recent decades, the findings suggest that improved pollution control has managed to offset its damaging effects on ...

LAST 30 PRESS RELEASES:

Transforming treatment outcomes for people with OCD

Damage from smoke and respiratory viruses mitigated in mice via a common signaling pathway

New software tool could help better understand childhood cancer

Healthy lifestyle linked to lower diverticulitis risk, irrespective of genetic susceptibility

Women 65+ still at heightened risk of cervical cancer caused by HPV

‘Inflammatory’ diet during pregnancy may raise child’s diabetes type 1 risk

Effective therapies needed to halt rise in eco-anxiety, says psychology professor

Nature-friendly farming boosts biodiversity and yields but may require new subsidies

Against the odds: Endometriosis linked to four times higher pregnancy rates than other causes of infertility, new study reveals

Microplastics discovered in human reproductive fluids, new study reveals

Family ties and firm performance: How cousin marriage traditions shape informal businesses in Africa

Novel flu vaccine adjuvant improves protection against influenza viruses, study finds

Manipulation of light at the nanoscale helps advance biosensing

New mechanism discovered in ovarian cancer peritoneal metastasis: YWHAB restriction drives stemness and chemoresistance

New study links blood metabolites and immune cells to increased risk of urolithiasis

Pyruvate identified as a promising therapeutic agent for ulcerative colitis by targeting cytosolic phospholipase A2

New insights into the clinical impact of IKBKG mutations: Understanding the mechanisms behind rare immunodeficiency syndromes

Displays, imaging and sensing: New blue fluorophore breaks efficiency records in both solids and solutions

Sugar, the hidden thermostat in plants

Personality can explain why some CEOs earn higher salaries

This puzzle game shows kids how they’re smarter than AI

Study suggests remembrances of dead played role in rise of architecture in Andean region

Brain stimulation can boost math learning in people with weaker neural connections

Inhibiting enzyme could halt cell death in Parkinson’s disease, study finds

Neurotechnology reverses biological disadvantage in maths learning

UNDER EMBARGO: Neurotechnology reverses biological disadvantage in maths learning

Scientists target ‘molecular machine’ in the war against antimicrobial resistance

Extending classical CNOP method for deep-learning atmospheric and oceanic forecasting

Aston University research: Parents should encourage structure and independence around food to support children’s healthy eating

Thunderstorms are a major driver of tree death in tropical forests

[Press-News.org] Physicist builds useful light source from harmonic generation