Investigation of Erbium-doped Tellurite Glasses for a Planar Waveguide Power Amplifier at 1.57μm

Er-doped tellurite waveguides for power amplifier applications

“…3 kWcm -2 . The temporal evolution of the probe beam power associated with the 10 ms pump pulse was captured at each probe wavelength, sometimes increasing at the front-end of the pulse then decaying toward the rear as previously observed in our earlier investigations of a similar multi-component composition [4]; revealing excited state energy transfer processes, such as Excited State Absorption (ESA). Figure 2 illustrates the measured gain corresponding to the two pump wavelengths, along with a simple gain calculation dependent upon the inversion factor, β, between the ground and the 4 I 13/2 energy manifold.…”

“…I sat ~ 3kWcm -2 at 1480 nm, and as such creates a higher inversion and therefore higher gain. However, the lifetime of the 4 I 11/2 level is sufficiently long to allow a strong ESA transition, assisted by the excitation of two vibrational modes, promoting an Er 3+ ion to its 4 F 9/2 energy state, leading to reduced gain, or even additional loss, at the longer probe wavelengths, Figure 2 Instead for the in-band pumped gain spectrum, Figure 2(b), there appears to be a different ESA process, from 4 I 13/2 to 4 I 9/2 , where one vibrational phonon is excited along with the absorption of a photon with a wavelength that covers pretty much the entire investigated range. It is noteworthy that there is a small spike around 1572 nm, which again corresponds to the gap in the vibrational modes around 550cm -1 .…”

“…Typically Tellurite glasses are considered a low-phonon energy host for rare earths, with the vibrational mode energy spectrum confined to ħω max <800 cm -1 . Generally this means that if there is significant population in the 4 and rapidly de-excite the 4 I 11/2 energy level of the latter, based on a zinc oxide glass former, magnesium oxide glass modifier, and a borate additive to capitalise on the more energetic stretching vibrations of the B-O -bonds, up to about 1400 cm -1 [5]. Efficient energy transfer from the excited Yb 3+ to Er 3+ was observed, although at the expense of the 4 I 13/2 manifold lifetime as well, τ f~3 ms.…”

Optical Properties of Erbium-Doped Tellurite Glasses: A Review and Bibliometric Study

“…It is believed increasing the light optical absorption. Therefore, tellurite glasses doped by erbium were developed for application as an optical amplifier, a potential high-energy capacitor, a laser host, and the others [10][11][12][13]. There are various types of glass material compositions with a host of tellurium dioxide which is then doped with erbium ions.…”

“…The fabrication of tellurite glass mostly uses the quenching melt technique with a certain temperature so that an amorphous arrangement is obtained in the developed material [7][8][9][10][11][12][13][14]. The process of making tellurite glass with this technique is not easy, so not many researchers are concerned about the development of tellurite glass material.…”