Physikalisch-Technische Bundesanstalt

To cope with the increasing requirements on bandwidth, Dense Wavelength Division Multiplexing (DWDM) systems are used to an ever increasing extent in optical telecommunication. At present, the wavelength range is constantly extending and, at the same time, the channel distances are getting smaller. For the calibration of measuring systems and the support of networks, wavelength references in the range between 1480 nm and 1640 nm with a relatively high accuracy are required. Due to their high intrinsic stability, fibre lasers are particularly suited as high-precision frequency standards.

The availability of optical clocks and frequency combs allows the stability of optical clocks to be transferred to the near-infrared spectral range and to be directly used there for stabilization of a fibre laser. Therewith, a frequency reference with a relative stability of σ _y< 1 ^.10^-14 at an averaging time of 1s and an accuracy of a few Hz is available in this wavelength range.

The further development of frequency-stable fibre lasers is another field of work of this Working Group.