Er, Yb: phosphate glass

(1) What is an Er Yb: phosphate glass?

The glass doped with Er as well as ytterbium ions is Er glass; Glasses doped with erbium, ytterbium, and chromium ions are also erbium glasses; the double adhered crystal of erbium glass and white glass is likewise erbium glass. The glass substratum in question is not typical glass yet phosphate glass. This paper mainly introduces Er, Yb doped glass.

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

(2) What is phosphate glass?

Phosphate glass is a glass material that primarily contains phosphorus pentoxide (P2O5) and generally likewise consists of other chemical elements. It can be made used as a laser gain tool wholesale and fiber. Its primary advantage is its high compatibility with rare-earth ions (see rare-earth-doped gain media), such as Erbium (Er3+), ytterbium (Yb3+), and neodymium (Nd3+) ions.

To put it simply, the phosphate glass varieties can be doped with a high concentration of laser-active uncommon planet ions without causing adverse effects such as clustering, which will certainly produce a quenching impact and influence the efficiency of the laser. The doping concentration in phosphate erbium-doped fiber is much greater than that in quartz fiber, and it can rise by several percentage points. The high doping concentration of phosphate enables short-fiber lasers and amplifiers. Which are not the only advantages of glass yet; likewise include:
The short fiber laser resonator can get a large cost-free spectrum range, making it easier to attain single-frequency operation.

Dispersed response lasers are short, whereas highly drugged phosphate fibers allow for much more effective pump absorption.

Ultrashort pulsed fiber lasers are much less at risk of nonlinear impacts if they use shorter fibers.

(3) What's the mechanism of Er glass?

Phosphate glass combines a long lifetime (~ 8 ms) of 4I13/2 Er3+ top laser level with a reduced (2-3 ms) lifetime of 4I11/2 Er3+ level that continues to be in resonance with Yb3+ 2F5/2 terminated upstate. Quick non-radiative multi-phonon entertainment from 4I11/2 to 4I13/2 degree significantly lowers the back-energy transfer and up-conversion losses because of the interaction between Yb3+ and Er3+ ions, delighted at the 2F5/2 along with the 4I11/2 degrees, specifically.

Essentially continuously, erbium-ytterbium-doped phosphate glass is pumped with wavelengths around the 975-nm absorption height of Yb3+ ions. That results in the excitation of the ytterbium ions. Afterward, Yb ions may move the excitation power to surround erbium ions. After a reliable power transfer, one first has an Er3+ ion in the 4I11/2 state (even more especially, a Stark degree manifold), which has similar excitation energy as the Yb3+ ions. From that state, the ions usually undertake a rapid non-radiative change to the state 4I13/2, routinely utilized as the leading laser degree. Such non-radiative changes take place based upon multi-phonon discharge, supplied that the phonon power of the item is high and appropriate (which holds for silica fibers, for instance).

(4) Application of Er Yb: glass in Er glass laser

Er, glass is additionally an exceptional item for upconversion luminescence. Laser obtained the green and red laser from erbium-doped glass fiber, and individuals also observed violet upconversion light. The upconversion luminescence of Er: phosphate glass delighted by Nd: YAG was explored. The upconversion laser will certainly be useful in great deal of applications.
Er, glass is a pure three-level laser device. As a result of this, it requires pumping nearly all the energetic glass aspects. The non-pumped areas give laser light absorption losses. Regarding the traditional pole plan, the non-pumped rod needs to be as brief as possible.

The optical excitation of the Yb, Er glasses (especially chromium-free ones) mostly utilize Yb ions. The only Yb absorption band depends on the near-infrared spectral range (900-- 1000 nm). Water termination in this spooky range is 1 cm-1. Therefore, Er glass can drastically lower the water-cooled laser efficiency due to pump light absorption in the water layer bordering the flashlamp and the laser pole.

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