(1) What is Er glass ？ Er3+, Yb3+ co-doped phosphate glass (Er, Yb: phosphate glass) is a popular as well as typically utilized active device for lasers generating in the "eye-safe" spectral variety of 1,5-1,6 µm. (2) What's the mechanism of erbium glass? Phosphate glass incorporates a long lifetime (~ 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 resonance with Yb3+ 2F5/2 fired up state. Quick non-radiative multi-phonon leisure from 4I11/2 to 4I13/2 level considerably reduces the back-energy transfer and up-conversion losses because of the communication in between Yb3+ and Er3+ ions, delighted at the 2F5/2 along with the 4I11/2 amounts, specifically. Basically continually, erbium-ytterbium-doped phosphate glass is pumped with wavelengths around the 975-nm absorption elevation of Yb3+ ions. That results in the excitation of the ytterbium ions. Afterwards, the excitation power might be transferred to neighboring erbium ions. After an effective power transfer, one first has an Er3+ ion in the 4I11/2 state (much more especially, a Stark level manifold), which has similar excitation energy as the Yb3+ ions. From that state, the ions normally undergo a quick non-radiative shift to the state 4I13/2, regularly utilized as the top laser degree. Such non-radiative shifts happen based upon multi-phonon discharge, supplied that the phonon energy of the item is high enough (which holds for silica fibers, for example). (3) Application of Er, Yb: glass in Erbium glass laser. Er glass is additionally an exceptional material for upconversion luminescence. Laser acquired the eco-friendly and red laser from erbium-doped glass fiber, and also people furthermore observed violet upconversion light. The upconversion luminescence of Er: phosphate glass delighted by Nd: YAG were explored. The upconversion laser will be really useful in great deals of applications. Er glass is a pure three-level laser medium. Because of this, it should pump virtually all the energetic glass elements. The non-pumped areas are a source of laser light absorption losses. When it comes to the traditional rod arrangement, the non-pumped pole must be as short as feasible. The optical excitation of the Yb - Er glasses (particularly chromium-free ones) happens primarily by means of Yb ions. The only Yb absorption band hinges on the near-infrared spectral range (900-- 1000 nm). Water termination in this spectral array is 1 cm-1. For this reason, the water-cooled laser effectiveness can be significantly decreased as a result of pump light absorption in the water layer bordering the flashlamp and also the laser rod.
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