High Efficiency 1.9 Kw Single Diode Laser Bar Epitaxially Stacked With a Tunnel Junction

Al-free Diode Laser Bar

Al-free active diode laser emitting near 970 nm wavelength has been optimized for high electricalto-optical power conversion efficiency. There are numerous key contributors such as scattering and absorption losses, band alignment, Joule heating, carrier leakage and below-threshold losses that contribute to power loss mechanisms. We report on improvement from 50% to a record high 70% power conve...

High-efficiency diode-pumped Tm:YAG ceramic laser

A high efficient Tm:YAG ceramic laser at 2007 nm pumped by a diode laser was demonstrated. The laser performances with Tm doping concentrations of 4 at.% and 6 at.% were comparatively analyzed. The continuous-wave (CW) laser powers up to 2.11 W and 1.68 W have been obtained for Tm:YAG ceramics at 6 at.% and 4 at.% doping levels, corresponding to the slope efficiencies of 43.6% and 53.8% respect...

InGaN/GaN light-emitting diode with a polarization tunnel junction

Origin of InGaN/GaN light-emitting diode efficiency improvements using tunnel-junction-cascaded active regions

This Letter investigates the efficiency enhancement achieved by tunnel junction insertion into the InGaN/GaN multi-quantum well (MQW) active region of blue light emitting diodes (LEDs). The peak quantum efficiency of such LED exceeds 100%, but the maximum wall-plug efficiency (WPE) hardly changes. However, due to the increased bias, the WPE peaks at much higher input power, i.e., the WPE droop ...

Diode-pumped 1 kW Q-switched Nd:YAG rod laser with high peak power and high beam quality.

We have demonstrated high-peak-power generation at 1 kW average power by applying an acousto-optic Q switch to a quasi-cw diode-pumped Nd:YAG master oscillator power amplifier. We achieved a maximum peak power of 2.3 MW by driving the Q switch in burst mode. The average repetition rate was 6 kHz. The corresponding beam quality was M2 = 9.