(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 likewise erbium glasses; the double bound crystal of erbium glass and also white glass is also erbium glass. The glass substrate concerned is not typical glass yet phosphate glass. This paper primarily presents Er, Yb doped glass.
Er3+, Yb3+ co-doped phosphate glass (Er, Yb: phosphate glass) is a prominent and generally used active tool for lasers creating in the "eye-safe" creepy collection of 1,5-1,6 µm.
(2) What is phosphate glass?
Phosphate glass is a glass product that mainly contains phosphorus pentoxide (P2O5) as well as normally additionally includes various other chemical elements. It can be utilized as a laser gain tool wholesale and fiber. Its major benefit is its high compatibility with rare-earth ions (see rare-earth-doped gain media), such as Erbium (Er3+), ytterbium (Yb3+), and also neodymium (Nd3+) ions. Simply put, the phosphate glass varieties can be doped with a high concentration of laser-active rare earth ions without triggering damaging effects such as clustering, which will generate a quenching result and affect the performance of the laser. The doping focus in phosphate erbium-doped fiber is a lot higher than that in quartz fiber, as well as it can raise by several portion factors. The high doping focus of phosphate allows short fiber lasers and amplifiers, which are not the only advantages of the glass yet likewise consist of:
The short fiber laser resonator can get a huge totally free spectrum variety, making it simpler to accomplish single-frequency procedure.
Dispersed comments lasers are short, whereas very drugged phosphate fibers enable a lot more effective pump absorption.
Ultrashort pulsed fiber lasers are much less susceptible to nonlinear results if they make use of much shorter fibers.
(3) 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 remain in resonance with Yb3+ 2F5/2 fired up state. Quick non-radiative multi-phonon leisure from 4I11/2 to 4I13/2 level considerably decreases the back-energy transfer and up-conversion losses due to the interaction between Yb3+ and Er3+ ions, thrilled at the 2F5/2 along with the 4I11/2 degrees, respectively.
Essentially continuously, erbium-ytterbium-doped phosphate glass is pumped with wavelengths around the 975-nm absorption elevation of Yb3+ ions. That brings about the excitation of the ytterbium ions. Later, Yb ions might move the excitation power to neighboring erbium ions. After an effective power transfer, one first has an Er3+ ion in the 4I11/2 state (far more especially, a Stark level manifold), which has comparable excitation energy as the Yb3+ ions. From that state, the ions usually go through a quick non-radiative shift to the state 4I13/2, frequently made use of as the leading laser degree. Such non-radiative adjustments happen based upon multi-phonon discharge, gave that the phonon power of the product is high as well as sufficient (which holds for silica fibers, for instance).
(4) Application of Er, Yb: glass in Erbium glass laser
Er, glass is also an extraordinary item for upconversion luminescence. Laser obtained the green and also red laser from erbium-doped glass fiber, as well as people likewise observed violet upconversion light. The upconversion luminescence of Er: phosphate glass delighted by Nd: YAG was discovered. The upconversion laser will absolutely be really useful in great deals of applications.
Er, glass is a pure three-level laser tool. Due to this, it needs to pump almost all the energetic glass aspects. The non-pumped locations provide laser light absorption losses. When it comes to the conventional pole arrangement, the non-pumped pole requires to be as brief as possible.
The optical excitation of the Yb, Er glasses (particularly chromium-free ones) happens primarily utilizing Yb ions. The only Yb absorption band hinges on the near-infrared spooky range (900-- 1000 nm). Water discontinuation in this spooky range is 1 cm-1. For this reason, Er glass can considerably lower the water-cooled laser efficiency as a result of pump light absorption in the water layer surrounding the flashlamp and also the laser rod.