LD-pumped 2.8 μm Er:Lu₂O₃ ceramic laser with 6.7 W output power and >30% slope efficiency

Abstract

We present a high-power, high-efficiency, laser-diode-pumped 2.8 μm Er:Lu2O3 ceramic laser generating record power at room temperature. Careful thermal management and pump-radius enlargement resulted in a continuous-wave output power of 6.7 W at 2845 nm, with a 30.2% slope efficiency. To our knowledge, this is the highest output power and slope efficiency ever achieved from a laser-diode-pumped 3 μm Er-doped ceramic laser. These results confirm the possibility of generating high-output-power, high-efficiency laser using transparent ceramics.

Influence of annealing on microstructures and properties of Yb:Lu2O3 transparent ceramics

“…[1][2][3][4][5][6] Several reports on laser performances have been published for Ln 2 O 3 transparent ceramics doped with rare earth ions (RE 3+ ) for solid-state laser applications. [7][8][9][10][11] Among these combinations of RE:Ln 2 O 3 , Yb:Lu 2 O 3 transparent ceramics particularly show great potential for 1 μm high-power solid-state laser applications owing to the high thermal conductivity, which is advantageous for heat removal. [12][13][14] Importantly, the ionic size and atom mass of Yb 3+ are very close to those of Lu 3+ , resulting in a minimal decrease in the thermal conductivity in Yb:Lu 2 O 3, even under high doping concentration.…”

“…Sesquioxides including Y 2 O 3 , Lu 2 O 3 and Sc 2 O 3 (Ln 2 O 3 , Ln = Y, Lu, Sc) and their mixed solid solution transparent ceramics have attracted considerable interest as hosts for laser gain media due to their excellent thermal‐mechanical properties, low phonon energy, wide transparent wavelength range, and low fabrication temperature far below the melting point 1–6 . Several reports on laser performances have been published for Ln 2 O 3 transparent ceramics doped with rare earth ions (RE 3+ ) for solid‐state laser applications 7–11 . Among these combinations of RE:Ln 2 O 3 , Yb:Lu 2 O 3 transparent ceramics particularly show great potential for 1 μm high‐power solid‐state laser applications owing to the high thermal conductivity, which is advantageous for heat removal 12–14 .…”

Spectroscopy and efficient laser operation around 2.8 μm of Er:(Lu,Sc)2O3 sesquioxide ceramics

“…So far ~2.8 µm emission from Er 3+ sesquioxide lasers based on Lu 2 O 3 [19][20][21] and Y 2 O 3 [22][23][24] ceramics has been studied. Very recently, Yao et al reported on a diodepumped Er:Lu 2 O 3 ceramic laser delivering 6.7 W at 2845 nm with a slope efficiency of 30.2%, representing record-high results in terms of output power and efficiency obtained so far [19]. Er 3+ -doped Sc 2 O 3 transparent ceramics have been also synthesized [25,26].…”

Single Longitudinal Mode and Widely Tunable Er:Y2O3 Ceramic Laser at ∼ 2.7 μm

“…Compared with sesquioxides single crystals, ceramics can be prepared at temperatures much lower than the melting points, and with advantages such as volume scalability with low cost, versatile structures, and/or varying doping profiles-all of which make it suitable as widespread materials for efficient and high power ∼3 µm laser operation [11]. In recent years, with the development of fabrication technology, efficient ∼3 µm laser operation based on Er:Y 2 O 3 and Er:Lu 2 O 3 ceramics have been successfully demonstrated at either room temperature or with cryogenic cooling [12], [13], [14], [15], [16], [17], [18].…”