The focus of dark sources, as the focus of light sources, has been shifting in recent years, according to new research.
“The main reason has been that the focus on light has been declining,” says Matthew Hsu, professor of applied mathematics and statistics at the University of Washington in Seattle, who was not involved in the research.
Hsu’s research is the first to quantify the shift in focus, focusing on light sources that have become less visible to the naked eye, such as LEDs and laser lights.
In the past, it was common to think of light as a continuous stream of photons passing through an opaque material like glass or a film.
But with the advent of the digital camera, cameras have also become more capable at capturing light and capturing more of it.
“Light is the same thing as energy, so we need to understand the physics of light,” Hsu says.
HSU’s research shows that even the simplest light sources are capable of producing an effect called phase shift, which is the shift between two different wavelengths of light.
For instance, when a light beam passes through a film of paper or a glass, it creates a different pattern of wavelengths.
Hsus researchers looked at the brightness of light from different light sources and found that the brightest light from LED lights produces phase shift at wavelengths as low as 400 nanometers (nm).
This is roughly the wavelength of a single human hair, which can be found in the wavelength range of 300 nanometers to about 1,200 nm.
In fact, the wavelength that makes the best use of LED light is about 600 nm, or about a half-millionth of a wavelength, and the wavelength shift is much more powerful than that.
The researchers also found that these light sources also produce phase shifts at much higher wavelengths, about 3,000 nm, which make them more useful as light sources for low-power lasers.
“They make light beams very fast, so they are also very easy to use,” says Hsu.
Huanqiu Tang, an assistant professor of electrical engineering at the Massachusetts Institute of Technology in Cambridge, has studied LED light sources before.
He has shown that the brightness changes from different sources can be useful for identifying the source.
Tang says phase shift is important because it gives a more precise idea of what the source is made of.
“In this case, it is not just a matter of what material is being reflected,” he says.
“It is also important to know the nature of the light, the direction of the radiation, and how the light is absorbed.”
The researchers found that LED light could be used to measure the distance between a light source and a material.
In a recent paper, Tang and Hsu analyzed the spectral signatures of different types of LEDs, including LED bulbs, LED displays, and LEDs that emit light from two sources simultaneously.
They found that when the intensity of the LED light changes, the spectral signature changes as well.
The authors found that light emitted from a single LED can be used for phase shifting, while the light emitted by multiple LEDs can be a good measure of distance.
In other words, the light from multiple LEDs will produce phase shift even when there is no source.
The study also found a strong correlation between the brightness and phase shift of different LED lights.
For example, when the brightness is high, the phase shift becomes less intense as the distance increases.
This is consistent with a theory of quantum optics, in which light waves that travel through a medium have an intrinsic shape, known as the curvature of space, that determines the speed at which light travels.
“When the curvatures are large, it can affect the way light moves through a material,” Tang says.
The findings were published today in the journal Optics Letters.
The team also discovered that the intensity changes with distance, so that the light with higher intensity has more phase shift.
“We are trying to understand how the quantum properties of light can be controlled,” Hsuses says.
For more about the research, check out this video by the National Science Foundation.
Hsin Chen, a research fellow at the National Center for Atmospheric Research, led the study.
Chen has studied optical effects such as optical phase shift for a decade.
In 2010, he and his team published a paper in the Proceedings of the National Academy of Sciences that showed that the quantum effects of light caused by photons could have important implications for the development of low-cost and efficient light-emitting devices.
“These optical effects can have important applications in quantum information technology,” Chen says.