Design and fabrication of low beam divergence and high kink-free power lasers

Qiu, Bocang; McDougall, S.D.; Liu, Xuefeng; Bacchin, G.; Marsh, J.H.

doi:10.1109/jqe.2005.853359

Cited by 62 publications

(16 citation statements)

References 12 publications

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“…In ref. 9, it is shown that kink levels increased with an increase in cladding layer thickness in both sides of a mesa. However, a thick cladding layer in both sides of the mesa necessarily leads to an increase in threshold current owing to lateral expansion of the injected current.…”

Section: Introductionmentioning

confidence: 94%

“…It should be noted that spatial hole burning becomes less significant with increasing number of steps in the guiding layers, which leads to stable single transverse mode oscillations with increasing number of steps in the guiding layers. If the injected current is much higher, spatial hole burning becomes significant, 3,9) and the modal gain of the first-order mode exceeds that of the fundamental mode, leading to kinks in the I-L curves. Figures 5 and 6 show hole concentration distributions as a function of the distance from the center of the mesa in the horizontal direction in the active layers for d ¼ 250 and 300 nm, respectively.…”

Section: Figures 3 and 4 Show Electron Concentration Distributionsmentioning

confidence: 99%

“…Therefore, higher kink levels are required to achieve lasing in the fundamental transverse mode with high light output power maintaining high slope efficiency and high fiber coupling efficiency. To date, to increase kink levels, coupling of the optical field to the lossy metal layers outside the ridge, 7) forming highly resistive regions in both sides of a ridge stripe, 8) and incorporation of a graded V-shape layer 9) have been proposed. In ref.…”

Section: Introductionmentioning

confidence: 99%

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Ridge-Type Semiconductor Lasers with Optical Antiguiding Layers for Horizontal Transverse Modes: Dependence on Step Positions

Shomura

Numai

2009

jjap

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The dependence of the lasing characteristics of a novel ridge structure with optical antiguiding layers for horizontal transverse modes on step positions in the guiding lasers is theoretically investigated. It is found that steps in both the upper guiding layer, which is adjacent to the p-cladding layer, and the lower guiding layer, which is adjacent to the n-cladding layer, increase kink level and the contribution of the steps in the upper guiding layer is higher than that of the steps in the lower guiding layer. It is also revealed that steps in the upper guiding layer decrease threshold current and those in the lower guiding layer slightly increase threshold current.

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Section: Introductionmentioning

confidence: 94%

Section: Figures 3 and 4 Show Electron Concentration Distributionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Ridge-Type Semiconductor Lasers with Optical Antiguiding Layers for Horizontal Transverse Modes: Dependence on Step Positions

Shomura

Numai

2009

jjap

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“…For improvement in the mode-locking performance of mode-locked lasers, this epitaxial material was modified by reducing the QWs from 5 to 3 and inserting a far-field reduction layer. This leads to a lower differential gain and increase in the mode size [10]. Figure 1 shows the simulation results of optical intensity in the material.…”

Section: Materials Design and Device Fabricationmentioning

confidence: 99%

AlGaInAs/InP Based Five & Three Quantum Wells Mode Locked Laser Diodes: A Comparative Study

Akbar

Hanif

Naeem

et al. 2020

ELEKTRON ELEKTROTECH

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Comparison of performance of semiconductor mode-locked laser diodes fabricated using AlGaInAs/InP material containing 5 and 3 quantum wells (QWs) inside the active region is reported. The simulations and experimental results show that lasers containing five QWs materials produce larger beam divergence and temporally broader optical pulses. For improvement in the mode-locking of lasers and reducing the far-field pattern, the number of QWs inside the active region was decreased from five to three and a far-field decreasing layer along with a thick spacer layer were introduced in the n-cladding region of epitaxial material. Before growing the material, simulations were carried out to optimise the design. The lower optical confinement factor and higher gain saturation energy of three QWs based mode-locked lasers provide higher average and peak output power, reduced and symmetric far-field pattern, better radio frequency (RF) spectra, shorter optical pulses, and stable optimal mode-locking for a wide range of gain current and saturable absorber reverse voltage.

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“…Further reduction of the VFF can be accomplished by inserting a VSWW into the n-cladding layer [14]. The refractive index profile of the new structure (S 2 ) is shown in Figure 1.…”

Section: Structure Design and Simulationmentioning

confidence: 99%

Waveguide Design Optimization for Long Wavelength Semiconductor Lasers with Low Threshold Current and Small Beam Divergence

Al-Muhanna¹,

Alharbi²,

Salhi³

2011

JMP

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Long wavelength GaSb-based quantum well lasers have been optimized for high coupling efficiency into an optical system. Two approaches were used to reduce the vertical far-field. In the first approach we showed the use of V-shaped Weaker Waveguide in the n-cladding layer dramatically reduces vertical beam divergence without any performance degradation compared to a conventional broad-waveguide laser structure. Starting from a broad waveguide laser structure design which gives low threshold current and a large vertical far-field (VFF), the structure was modified to decrease the VFF while maintaining a low threshold-current density. In a first step the combination of a narrow optical waveguide and reduced refractive index step between the waveguide and the cladding layers reduce the VFF from 67? to 42?. The threshold current density was kept low to a value of ~190 A/cm2 for 1000 × 100 µm2 devices by careful adjustment of the doping profile in the p-type cladding layer. The insertion of a V-Shaped Weaker Waveguide in the n-cladding layer is shown to allow for further reduction of the VFF to a value as low as 35? for better light-coupling efficiency into an optical system without any degradation of the device performance. In the second approach, we showed that the use of a depressed cladding structure design also allows for the reduction of the VFF while maintaining low the threshold current density (210 A/cm2), slightly higher value compare to the first design

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Design and fabrication of low beam divergence and high kink-free power lasers

Cited by 62 publications

References 12 publications

Ridge-Type Semiconductor Lasers with Optical Antiguiding Layers for Horizontal Transverse Modes: Dependence on Step Positions

Ridge-Type Semiconductor Lasers with Optical Antiguiding Layers for Horizontal Transverse Modes: Dependence on Step Positions

AlGaInAs/InP Based Five & Three Quantum Wells Mode Locked Laser Diodes: A Comparative Study

Waveguide Design Optimization for Long Wavelength Semiconductor Lasers with Low Threshold Current and Small Beam Divergence

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