Power scaling and thermal lensing in 825  nm emitting membrane external-cavity surface-emitting lasers

Abstract

We present a membrane external-cavity surface-emitting laser (MECSEL) operating around 825 nm at room temperature. With a tuning range of 22 nm, the MECSEL fills the spectral gap between 810 nm and 830 nm, and extends the wavelength coverage of this category of high-beam-quality semiconductor lasers. For high-power operation, the pump spot size and cavity mode size can be enlarged in MECSELs. We apply this technique and demonstrate power scaling. The maximum output power is increased from 0.7 W to 1.4 W. Investigations on the beam quality reveal thermal lensing with a marginally changing M 2 value close to the diffraction limit.

Thermal Behavior and Power Scaling Potential of Membrane External-Cavity Surface-Emitting Lasers (MECSELs)

“…13. As can be seen, the = 825 nm MECSEL [10] is very close to the simulations as the structure thickness and material composition are very similar. However, for the = 780 nm-emitting AlGaAs-based MECSEL [13], the measured thermal resistance with SiC heat spreaders was about 5.9 K/W.…”

“…As it can be seen in Fig. 2, these advantages are remarkable and have pointed out to the possibility of using more affordable heat spreaders with lower thermal conductivity, such as SiC [8], [9], yet enabling power scaling to watt-levels [10], [11].…”

InGaN-diode-pumped AlGaInP VECSEL with sub-kHz linewidth at 689 nm

“…Targeting shorter (visible) fundamental wavelength emission, on the other hand, usually requires less efficient visible pumps, such as solid-state lasers [14], dye lasers [15], or even frequency-doubled IR VECSELs [16], thus increasing the total volume. For example, GaInP/AlGaInP, AlGaAs/AlGaInP, and GaInAsP/AlGaInP quantum well VECSELs with emission between 630 and 830 nm have been extensively studied when barrier-pumped at 532 nm [17][18][19], or in-well pumped at 640 nm [20].…”

Quantum dot membrane external-cavity surface-emitting laser at 1.5 μm

“…In turn, this enables to use heat-spreading materials with lower conductivity but more cost-effective as silicon carbide (SiC). Owing to these advantages, recent efforts have led to the demonstration of MECSELs emitting in the red and near-infrared [9][10][11][12][13][14][15] . In this paper, we focus our attention on the important 1.5 μm telecom region, where the DBR technology is particularly difficult due to the low refractive index contrast of InP-based materials.…”