What is Er glass

 (1) What is Er glass？

Er3+, Yb3+ co-doped phosphate glass (Er, Yb: phosphate glass) is a popular and normally used active device for lasers generating in the "eye-safe" spectral range of 1,5-1,6 µm.

(2) What's the system of erbium glass?

Phosphate glass integrates a long life time (~ 8 ms) of 4I13/2 Er3+ top laser degree with a low (2-3 ms) life time of 4I11/2 Er3+ level that continues to be in vibration with Yb3+ 2F5/2 fired up state. Quick non-radiative multi-phonon leisure from 4I11/2 to 4I13/2 level significantly reduces the back-energy transfer as well as up-conversion losses due to the communication between Yb3+ and also Er3+ ions, thrilled at the 2F5/2 along with the 4I11/2 levels, respectively.

Essentially continuously, erbium-ytterbium-doped phosphate glass is pumped with wavelengths around the 975-nm absorption height of Yb3+ ions. That leads to the excitation of the ytterbium ions. Afterwards, the excitation power might be transferred to close-by erbium ions-- see the short write-up on power transfer and likewise Fig. 1. After a reliable power transfer, one first has an Er3+ ion in the 4I11/2 state (far more especially, a Stark degree manifold), which has similar excitation energy as the Yb3+ ions. From that state, the ions generally undergo a fast non-radiative change to the state 4I13/2, regularly made use of as the upper laser level. Such non-radiative shifts happen based upon multi-phonon discharge, supplied that the phonon energy of the item is high sufficient (which holds for silica fibers, as an example).

(3) Application of Er, Yb: glass in Erbium glass laser.

Er glass is in addition a superb product for upconversion luminescence. Laser obtained the green as well as red laser from erbium-doped glass fiber, and also people similarly observed violet upconversion light. The upconversion luminescence of Er: phosphate glass delighted by Nd: YAG were investigated. The upconversion laser will be actually useful in great deals of applications.

Er glass is a pure three-level laser medium. Consequently, it needs to pump virtually all the energetic glass elements. The non-pumped zones are a source of laser light absorption losses. In the case of the conventional pole setup, the non-pumped pole must be as short as feasible.

The optical excitation of the Yb-Er glasses (specifically chromium-free ones) happens mostly using Yb ions. The only Yb absorption band depends on the near-infrared spectral range (900-- 1000 nm). Water termination in this spectral variety is 1 cm-1. For this reason, the water-cooled laser performance can be substantially lowered as a result of pump light absorption in the water layer bordering the flashlamp as well as the laser rod.