Spectroscopy of Yb³⁺ in the disordered Na_2/7Gd_4/7MoO₄ crystal with a scheelite‐type cation‐deficient structure

Abstract

The creation of cation vacancies in the scheelite‐type framework leads to the formation of Na2/7Gd4/7MoO4 compound, where cationic sites are shared by Na+, Gd3+, and vacancies. The spectroscopic properties at ∼1 µm of this novel disordered Yb3+‐doped crystal, grown by the Czochralski method, have been investigated. The absorption and fluorescence spectra at 10 and 300 K provide the important information on the absorption and emission cross‐sections as well as the Stark energy‐level positions of Yb3+ ions in the crystal. The wavelength dependence of the gain cross‐section has been determined, which predicts a broad tuning range and potential sub‐100‐fs laser pulse generation. The laser parameters βmin, Isat, and Imin have been calculated, and the perspectives for applications as a laser‐active material have been discussed.

Атомистическое моделирование натрий-гадолиниевого молибдата стехиометрического (Na-=SUB=-1/2-=/SUB=-Gd-=SUB=-1/2-=/SUB=-MoO-=SUB=-4-=/SUB=-) и катион-дефицитного (Na-=SUB=-2/7-=/SUB=-Gd-=SUB=-4/7-=/SUB=-MoO-=SUB=-4-=/SUB=-) составов

“…В последнее время в ряде работ [9][10][11][12][13][14] изучался натрий-гадолиниевый молибдат нестехиометрического состава Na 2/7 Gd 4/7 MoO 4 (NG 2 M), который обладает катион-дефицитной структурой и содержит согласно но-минальному составу 1/7 незанятых катионных позиций.…”

Effect of La3+ incorporation on the spectroscopic properties of Yb3+ -doped Y1−x La x Ca4 O(BO3 )3 (x = 0.09 and 0.25) crystals

“…Following the emergence of the efficient pumping sources of high‐power InGaAs laser diodes (LDs), Yb 3+ has been recognized to be the most promising lasing ion which can be employed instead of Nd 3+ in laser operating at 1 µm . The advantages and disadvantages of Yb 3+ ion over Nd 3+ ion in laser hosts has been well described in Ref.…”

“…The simple 4f 13 electronic structure of Yb 3+ , ensures the small quantum defect (∼11%) and the absence of some detrimental de‐excitation processes ( e.g ., concentration quenching, excited state absorption, and upconversion) . Additionally, the long upper laser level lifetime (millisecond scale) enhances the energy storage capacity . More importantly, Yb 3+ exhibits favorably broad gain bandwidth due to the strong electron–phonon coupling, which is a prerequisite for the generation of ultrashort laser pulses .…”