Al2O3 half-wave films for long-life cw lasers

Ladany, I.; Ettenberg, M.; Lockwood, H. F.; Kressel, H.

doi:10.1063/1.89298

Cited by 92 publications

(8 citation statements)

References 4 publications

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“…Similar enhancements in the device output have been observed in various systems, e.g., GaAs p-n junctions, 20 AlGaAs/GaAs light-emitting diodes, 21 and laser diodes, 22 and II-VI incoherents 1 and coherent 2 emitters, and were attributed to an annealing of defects enhanced by nonradiative recombination. 20 Since in our case the increase was stronger at low energies and low beam currents, i.e., when the generated carriers were created predominantly near the surface and reached the QW after diffusion, it is possible that annealing resulted in a modification of the properties of the GRIN layers.…”

Section: B Average Degradation Behavior: Influence Of Structural Parmentioning

confidence: 67%

Combined transmission electron microscopy and cathodoluminescence studies of degradation in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

Bonard

Ganière

Vanzetti

et al. 1998

Journal of Applied Physics

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We explored degradation in electron-beam-pumped Zn1−xCdxSe/ZnSe laser structures by combining cathodoluminescence (CL) measurements in a scanning electron microscope with transmission electron microscopy. The rate of degradation, measured as the decrease of the emitted CL intensity under electron bombardment, depends critically on the threading dislocation density and on the strain in the quantum well. Degradation occurs via the formation of dark spot defects, which are related to bombardment-induced networks of dislocation loops in the quantum well. These degradation defects often initiate where threading dislocations cross the quantum well. We propose a self-supporting dislocation climb mechanism activated by nonradiative recombination to explain the formation and propagation of the degradation defects.

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Section: B Average Degradation Behavior: Influence Of Structural Parmentioning

confidence: 67%

Combined transmission electron microscopy and cathodoluminescence studies of degradation in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

Bonard

Ganière

Vanzetti

et al. 1998

Journal of Applied Physics

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show abstract

“…There exist a major interest to improve power levels, reliability and reduce costs to levels that enable further access to mass markets for high volume optical memory, industrial (remote laser welding), offset printing, medical and telecommunication applications [1][2]. Due to extremely high power densities at laser mirror facets, a protective layer is required which hinders moisture, ambient atmosphere and other influences from oxidizing and eroding the facets and laser crystal, and prevents "surface erosion" [3] and subsequent catastrophic optical mirror damage (COMD). Such a protective layer is commonly named a passivation layer and several types of facet passivation techniques have proven very successful in raising power and reliability of telecommunications 980nm emitting pump lasers for inversion of erbium doped fiber amplifiers (EDFA).…”

Section: Introductionmentioning

confidence: 99%

Nitride facet passivation raises reliability, COMD, and enables high-temperature operation of InGaAsP, InGaAs, and InAlGaAs lasers

Silfvenius¹,

Sun²,

Blixt³

et al. 2005

SPIE Proceedings

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The laser diode technology, underpinning applications such as data storage, industrial lasers and optical telecommunications, still suffers from reliability and longevity limitations, especially in high power applications. A main problem for these lasers arises from facet oxidation, leading to increased absorption, power degradation and COMD device failure. Typically, high power devices initially show a low linear degradation and after some 100 hours, the degradation accelerates in a nonlinear fashion, indicating a degradation runaway condition. This article reports performance and reliability improvements that are based on a process which atomically seals surfaces and eliminates oxidation by forming stable nitrides on laser facets. The dangling bond terminating technology suppresses accelerated degradation associated with optical density and heat at laser facets. The dangling bond termination is demonstrated by improved COMD, decreased degradation at CW operation and a constant linear degradation rate at different QW temperature conditions (nonlinear degradation indicates advancement in the oxidation/optical absorption/facet heating/oxidation spiral). The technology is applicable to a range of material systems and has previously been demonstrated on InAlGaAs and InGaAs (increased COMD to >270 and 470mW/µm respectively). The devices with the typically lowest COMD levels (AlInGaAs) show a remarkably low linear degradation rate of <0.5%/kh during at CW life test operation at 90˚C and a power level corresponding to 80W bar power. In addition to long term AlInGaAs laser life test results, this paper presents results on nitride facet passivation applied to 805nm InGaAsP devices, showing improved COMD to 400mW/µm and the initial CW life data confirms the general behavior of the previously life-tested InGaAs and InAlGaAs based devices.

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“…Facet degradation is well known for InGaAs/GaAs [1] and (AlGa)As [4] but there have been no reports on facet degradation in InGaN/GaN multiple quantum well lasers. While LD lifetimes of over 10.000 h have been reported, degradation is still a major issue.…”

Section: Introductionmentioning

confidence: 99%

Laser Diode Facet Degradation Study

et al. 2003

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We study the degradation behaviour of GaN gain guided laser diodes (LDs) on SiC substrates with cleaved facets and reflective coatings on none, one, or both facets. This allows us to demonstrate that in addition to volume effects there is a contribution of the laser facets to laser degradation. We observe that for the uncoated LDs the threshold current density is increasing considerably faster compared to LDs with mirror coatings. Degradation is observed during operation but not during storage at ambient conditions and thus expected to be photon or current induced. Operation of the uncoated laser in a nitrogen atmosphere reduces the degradation rate with respect to operation in air.

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Al2O3 half-wave films for long-life cw lasers

Abstract: Long-term operating-life data are reported for (AlGa)As cw laser diodes. The use of half-wave Al2O3 facet coatings is shown to eliminate facet erosion, allowing stable diode operation at constant current for periods in excess of 10 000 h.

Cited by 92 publications

References 4 publications

Combined transmission electron microscopy and cathodoluminescence studies of degradation in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

Combined transmission electron microscopy and cathodoluminescence studies of degradation in electron-beam-pumped Zn1−xCdxSe/ZnSe blue-green lasers

Nitride facet passivation raises reliability, COMD, and enables high-temperature operation of InGaAsP, InGaAs, and InAlGaAs lasers

Laser Diode Facet Degradation Study

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