The world's sharpest laser could improve radio communication in space

When leaving the field of science fiction, Laser now has a variety of real applications in such diverse areas as medicine, military, space research, and even nanotechnology. To ensure better performance and accuracy, scientists around the world are constantly looking for ways to improve the strength and sharpness of lasers. Within the framework of a new project, a team of researchers has developed the sharpest laser in the world with a line width of about 10 millihertz (MHz).

Previously, the line width of a laser will substantially cover the range of the emission spectrum (also known as the optical spectrum). In other words, the entire width of the frequency band of the radiation originates. Recently carried out by a group of scientists of the Physikalisch-Technische Bundesanstalt in Germany, the breakthrough might possibly improve the accuracy of the modern time-devices. Thomas Legero, a member of the research team, said:

Over the laser line width is smaller, the measurement of the frequency of the atom is accurate in an optical clock. This new laser will allow us to improve the quality of our watches.

The result of ten years of research has been called the impressive performance by a special Fabry-Perot resonator machine. Invented in 1899, the device has two mirrors to each other within a fixed double cone is parallel and is often used to measure the wavelengths of the light. According to the team, the line width of the laser actually depends on the distance between the two reflecting surfaces and their stability.

To build the world's sharpest laser, scientists had to ensure that the mirror was completely stable, despite changes in pressure and temperature and vibration related to seismic waves and ambient sounds. To eliminate the effects of Brownian motion, the type of involuntary motion as carbon in a fluid, researchers reconstructed the resonator of the single crystal silicon and then reduced the temperature to a -1 -150 degree C (about -238 degrees F).

Labortests new laser generated gave light waves at critical speeds of up to 200 trillion times per second for a total of 11 seconds of oscillating before losing their rhythm. The resulting wave trains measured about 3.3 million kilometers, or about ten times the distance of the moon from the earth. For the time being, the team is continuing to reduce the line width of the laser to slightly less than 1 mHz. If this happens, the technology could revolutionize radio communications in space. Besides significantly improving the accuracy of the measurement of electromagnetic radiation, the breakthrough could pave the way for a more efficient optical atomic clock.

The research results have recently been published in the journal Physical Review Letters.