A new study was able to create the first white lasers in the world through a series of experiments guided by the science behind monolithic semiconductors.
Monolithic semiconductor lasers, particularly the monolithic white laser, have the ability to release the complete spectrum of visible colors and can be used in numerous settings and industries. However, scientists fail to develop such laser type because it is very difficult to produce the epitaxial development of the diverse components needed for the varied color emission.
Researchers from the Arizona State University (ASU) Ira A. Fulton Schools of Engineering devised an innovative nanosheet, which is a thin semiconductor that can be comparable to one-fifth of human hair in thickness. The said device is composed of three parallel sections, each of which has a primary color to support in terms of laser action.
The findings of the study, published in the journal Nature Nanotechnology on Monday, July 27, show that the invention has the capability to function as a laser for any visible color and tune it fully from any of the elementary colors and those in between. The collation of the entire field will result in the emergence of the white color. The researchers have indeed proven that semiconductor lasers can emit over the entire range of visible color, which is the key feature needed to generate white light.
"The concept of white lasers first seems counterintuitive because the light from a typical laser contains exactly one color, a specific wavelength of the electromagnetic spectrum, rather than a broad-range of different wavelengths," explained Cun-Zheng Ning, lead author and professor at the School of Electrical, Computer and Energy Engineering at ASU. The common notion is that white light is a full mixture of all the wavelengths in the visible spectrum.
The results of the study may help to provide a breakthrough for laser technology. Through the findings of the study, lasers may exceed today's main light sources and possibly become a qualified substitute for light emitting diodes (LEDs).
Part of the study is the comparison of white light laser with current industry standards for display monitors. They found that their invention can provide approximately 70 percent more color than the presently available products. As lasers are more energy-efficient, brighter and more accurate in providing colors for display purposes such as in screen applications, its future is highly favorable.
Visible light communication is another interesting application that can benefit from laser technology. This technology, called the Li-Fi, uses room lighting to enhance illumination and communication at the same time. As opposed to Wi-Fi's usage of radio waves to provide wireless communication services, Li-Fi relies on the power of light. In the future, Li-Fi is said to become 10 times faster than Wi-Fi and white laser Li-Fi could possibly exceed the speed of LED-based Li-Fi by up to 100 times.
Further investigations and experiments are needed to polish this technology and overcome its limitations. The researchers are looking at using electricity to emit light as opposed to the present experiment, which required the researchers to pump electrons to attain the similar white light.
Photo: Chris Rosakranse | Flickr
