The scientists from this collaboration see further optimization possibilities. In reality, however, there is always a certain linewidth. 200 trillion times per second, it only gets out of sync after 11 seconds. For researchers, this is a measure for the light wave&food factory lighting suppliers39;s regular frequency and linewidth.Lasers were once deemed a solution without problems – but that is now history. This new laser will enable us to decisively improve the quality of our clocks", PTB physicist Thomas Legero explains. Similar to an organ pipe, the resonator length determines the frequency of the wave which begins to oscillate, i.end-ofTags: lasers, nist labs, europe, fiber, science. Only by comparing these two lasers was it possible to prove the outstanding properties of the emitted light.One of the two silicon resonators (photo: PTB)No one had ever come so close to the ideal laser before: theoretically, laser light has only one single color (also frequency or wavelength)."In the future, it is planned to disseminate this light also within a European network.

"The smaller the linewidth of the laser, the more accurate the measurement of the atom's frequency in an optical clock. The laser’s frequency stability – and thus its linewidth – then depends only on the length stability of the Fabry-Pérot resonator. Laser light is used in numerous applications in industry, medicine and information technologies.For this reason, the scientists of this collaboration manufactured the resonator from single-crystal silicon which was cooled down to a temperature of -150 °C. At PTB, the ultrastable light from these lasers is already being distributed via optical waveguides and is then used by the optical clocks in Braunschweig. Lasers have brought about a real revolution in many # fields of research and in metrology – or even made some new fields possible in the first place. The resonator consists of two highly reflecting mirrors which are located opposite each other and are kept at a fixed distance by means of a double cone. Special stabilization electronics ensure that the light frequency of the laser constantly follows the natural frequency of the resonator. Although the light wave oscillates approx.One of a laser's outstanding properties is the excellent coherence of the emitted light. More than 50 years have passed since the first technical realization of the laser, and we cannot imagine how we could live without them today.Research has therefore focused on developing ever better lasers with greater frequency stability and a narrower linewidth.

Although the mirror layers are only a few micrometers thick, they dominate the resonator's length stability. In total, the resonator length, however, only fluctuates in the range of 10 attometers. The results have been published in the current issue of "Physical Review Letters". The resulting frequency variations of the laser therefore amount to less than 4 × 10–17 of the laser frequency.Since there was no other comparably precise laser in the world, the scientists working on this collaboration had to set up two such laser systems straight off. The Physikalisch-Technische Bundesanstalt has developed a laser with a linewidth of only 10 mHz. With novel crystalline mirror layers and lower temperatures, the disturbing thermal noise can be further reduced. This precision is useful for various applications such as optical atomic clocks, precision spectroscopy, radioastronomy and for testing the theory of relativity. The thermal noise of the silicon body is so low that the length fluctuations observed only originate from the thermal noise of the dielectric SiO2/Ta2O5 mirror layers. Within the scope of a nearly 10-year-long joint project with the US colleagues from JILA in Boulder, Colorado, a laser has now been developed at PTB whose linewidth is only 10 mHz.