Advancements in laser diode chip and packaging technologies for application in kW-class fiber laser pumping

High-Power Diode Laser Technology and Applications XIII

Peters

Duesterberg

et al. 2015

Self Cite

We report modeling and experimental results that demonstrate mechanisms limiting the output power of semiconductor lasers and a method experimentally yielding a dramatic increase of the maximum continuous wave output power. Unfolded cavity is used to achieve higher power and efficiency by improving the alignment between the carrier and photon density profiles in a long cavity device. This method offers reduced longitudinal spatial hole burning (LSHB) and lower photon density inside the laser cavity; therefore, it decreases possible LSHB and non-linear effects that could limit the output power of a semiconductor laser. We have demonstrated 29.5W output from 5.7mm long and 100um wide waveguide at 9xx nm using an unfolded cavity. A semiconductor laser with an unfolded cavity allows scaling of the output power by increasing the cavity length.

Section: Introductionmentioning

confidence: 99%

“…For applications requiring even greater optical power, optical sources have been developed wherein radiation from multiple high-power lasers is combined showing kW-level industrial diode lasers [1]. These sources are on the way to replace industrial lasers due to their superior performance than CO2 lasers [2].…”

Section: Introductionmentioning

confidence: 99%

29.5W continuous wave output from 100um wide laser diode

High-Power Diode Laser Technology and Applications XIII

Peters

Duesterberg

et al. 2015

Self Cite

“…Semiconductor lasers with reliable high output power are of great interest to many applications, especially recently for direct-diode and fiber lasers with kW-level output used in material processing [1]. The reliability and performance of these high-power systems are backed up by the reliability of the single emitters.…”

Section: Introductionmentioning

confidence: 99%

Reduced facet temperature in semiconductor lasers using electrically pumped windows

High-Power Diode Laser Technology XVII

Arslan

Gündoğdu

et al. 2019

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The self-heating of semiconductor lasers contributes directly to facet heating and consequently to the critical temperature for catastrophic optical mirror damage (COMD) but the existing facet engineering methods do not address this issue. Targeting this problem, we report experimental and modeling results that demonstrate a new method achieving facet temperatures significantly lower than the laser cavity temperature in GaAs-based high-power semiconductor lasers by using electrically isolated and pumped windows. Owing to monolithic integration, the method does not introduce any penalty on the efficiency and output power of the laser. Thermal modeling results show that the laser output facet can be almost totally isolated from heat generated in the laser cavity and near cold-cavity facet temperatures are possible. The method can be applied to single emitters, laser bars, and monolithically integrated lasers in photonic integrated circuits to improve their reliability and operating performance.

“…High power semiconductor lasers in the 9xx-nm spectral range have been used in a wide range of industrial applications and, lately, attracted much attention as pumping sources for kW-level fiber lasers and material processing 1 . Therefore, recent research efforts have concentrated on understanding the limitations and increasing the laser output power of GaAs-based semiconductor lasers [2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

IFVD-based large intermixing selectivity window process for high power laser diodes

Arslan

Şahin

Semiconductor Lasers and Laser Dynamics VIII

et al. 2018

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Catastrophic optical mirror damage (COMD) is a key issue in semiconductor lasers and it is initiated by facet heating because of optical absorption. To reduce optical absorption, the most promising method is to form non-absorbing mirror structures at the facets by obtaining larger bandgap through impurity-free vacancy disordering (IFVD). To apply an IFVD process while fabricating high-power laser diodes, intermixing window and intermixing suppression regions are needed. Increasing the bandgap difference (ΔE) between these regions improves the laser lifetime. In this report, SrF 2 (versus Si x O 2 /SrF 2 bilayer) and SiO 2 dielectric films are used to suppress and enhance the intermixing, respectively. However, defects are formed during the annealing process of single layer SrF 2 causing detrimental effects on the semiconductor laser performance. As an alternative method, Si x O 2 /S r F 2 bilayer films with a thin Si x O 2 dielectric layer is employed to obtain high epitaxial quality during annealing with small penalty on the suppression effect. We demonstrate record large ΔE of 125 meV. Broad area laser diodes were fabricated by the IFVD process. Fabricated high-power semiconductor lasers demonstrated conservation of quantum efficiency with high intermixing selectivity. The differential quantum efficiencies are 81%, 74%, 66% and 46% for as grown, bilayer protected, SrF 2 protected and QWI lasers, respectively. High power laser diodes using bilayer dielectric films outperformed single-layer based approach in terms of the fundamental operational parameters of lasers. Comparable results obtained for the as-grown and annealed bilayer protected lasers promises a novel method to fabricate high power laser diodes with superior performance and reliability.