Browsing by Subject "Tunnel junction"
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Item Open Access Epitaxially-stacked high efficiency laser diodes near 905 nm(Institute of Electrical and Electronics Engineers Inc., 2022-12-01) Zhao, Yuliang; Yang, Guowen; Zhao, Yongming; Tang, Song; Lan, Yu; Liu, Yuxian; Wang, Zhenfu; Demir, AbdullahWe report on studying tunnel junctions and an optical cavity structure for developing epitaxially-stacked high-efficiency 905 nm high-power laser diodes. The GaAs tunnel junctions were explored via simulations and experiments to realize a high peak current density of 7.7 × 104 A/cm2 and a low specific resistance of 1.5 × 10-5 Ωcm2 with a high n-doping concentration of 6 × 1019 cm-3. Employing a low-loss epitaxial structure design, single-, double-, and triple-cavity structure laser diodes demonstrated power scaling by epitaxial stacking. Triple-cavity laser diodes have a low optical loss (0.42 cm-1) and generate a peak power of 83 W with a short cavity length of 750 μm at a limited current of 30 A. © 2009-2012 IEEE.Item Open Access High efficiency 1.9 Kw single diode laser bar epitaxially stacked with a tunnel junction(IEEE, 2021-04-21) Zhao, Y.; Wang, Z.; Demir, Abdullah; Yang, G.; Ma, S.; Xu, B.; Sun, C.; Li, B.; Qiu, B.We report on the development of a 940-nm diode laser bar based on epitaxially stacked active regions by employing a tunnel junction structure. The tunnel junction and the device parameters were systematically optimized to achieve high output and power conversion efficiency. A record quasi-continuous wave (QCW) peak power of 1.91 kW at 25 °C was demonstrated from a 1-cm wide bar with a 2-mm cavity length at 1 kA drive current (200 μs pulse width and 10 Hz repetition rate). Below the onset of the thermal rollover, the slope efficiency was as high as 2.23 W/A. The maximum power conversion efficiency of 61.1% at 25 °C was measured at 300 A. Reducing the heatsink temperature to 15 °C led to a marginal increase in the peak power to 1.95 kW.