Correct Answer: D
Explanation:
Scientists from Physikalisch-Technische Bundesanstalt (PTB) in Germany have developed the world’s sharpest laser with record - breaking precision.
This precision can be useful for various applications such as optical atomic clocks, radioastronomy, precision spectroscopy, testing the theory of relativity and carry out new precision measurements on ultracold atoms.
The laser (light amplification by stimulated emission of radiation) is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation.
Major difference between laser and other sources of light is that, laser emits light coherently.
Laser light is used in numerous applications in industry, medicine and information technologies.
It also brought about a real revolution in fields of research and in metrology, astronomy, and medical treatment.
Theoretically, laser light has only one colour, wavelength or frequency.
In reality, however, there is always a certain linewidth.
This newly developed laser has linewidth of only 10 miliHertz (0.01 Hz), - closer to the ideal laser than ever before.
Researchers also have found out that the emitted laser light’s frequency was more precise than what had ever been achieved before.