Excited State Absorption and Cross Sections for Er-Doped Glasses

Abstract

Pump-excited-state-absorption (ESA) measurements on Er3+-doped phosphates, fluorophosphates, and silicate bulk glasses indicate that ESA cross sections are approximately equal to ground state absorption (GSA) cross sections in the 800-nm band. The oscillator strengths of the ESA and GSA bands are also approximately equal, in qualitative agreement with Judd-Ofelt calculations. Fluorozirconate samples were found to have substantial populations in the upper excited states for the measurement conditions used and ESA transitions originating from four excited states were identified. Fluorozirconate fiber amplifiers and lasers at 1.55 μm, therefore, would have decreased efficiency for 800-nm pumping.

The route toward a diode-pumped 1-W erbium 3-/spl mu/m fiber laser

“…1): ESA 1 originates from the lower laser level [18] and has an absorption peak at 791 nm. ESA 2 from the upper laser level [17] has a maximum at longer wavelengths around 810 nm [29]. As is expected from the discussion in Section II, the increase of ESA 1 from the lower laser level has a negative influence (cf.…”

Erbium-doped glasses for fiber amplifiers at 1500 nm

“…As discussed in Section 11, the multiphonon emission rate for oxide glasses is high enough that only the 41,3/2 level can be appreciably populated. [89]. Fig.…”

“…Recently Zemon and coworkers have reported ESA measurements on bulk [88] and fiber [89] Er3+-doped glasses. Fig.…”

“…14 shows that the ESA cross section uZ4 for an AI/P-silica fiber exceeds the GSA, u ,~, over the complete pump band except Comparison of ESA and GSA cross-section spectra for AI/P silica. Data are from Zemon et al [89].…”

“…near 820 nm [89], and explains the higher gains realized for Alsilica amplifiers pumped at 820 nm [95]. In contrast, Fig.…”