Scientists have developed the world’s sharpest laser with record-breaking precision that can help make optical atomic clocks more precise as well as test Einstein’s theory of relativity.
Theoretically, laser light has only one colour, frequency or wavelength. In reality, however, there is always a certain linewidth.
Researchers, including those from the Physikalisch-Technische Bundesanstalt (PTB) in Germany, have now developed a laser with a linewidth of only 10 miliHertz (mHz) — closer to the ideal laser than ever before.
This precision is useful for various applications such as optical atomic clocks, precision spectroscopy, radioastronomy and for testing the theory of relativity. More than 50 years have passed since the first technical realisation of the laser, and we cannot imagine how we could live without them today.
Numerous applications
Laser light is used in numerous applications in industry, medicine and information technologies. Lasers have brought about a real revolution in fields of research and in metrology — or have even made some new fields possible in the first place.
One of laser’s outstanding properties is the excellent coherence of the emitted light. Ideally, laser light has only one fixed wavelength or frequency. In practice, the spectrum of most types of lasers can, however, reach from a few kHz to a few MHz in width, which is not good enough for numerous experiments requiring high precision.
