| 121. |
- Hjort, Filip, 1991, et al.
(författare)
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Advances in ultraviolet-emitting vertical-cavity surface-emitting lasers
- 2021
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 11686
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Konferensbidrag (refereegranskat)abstract
- We will give an overview of the progress in ultraviolet-emitting vertical-cavity surface-emitting lasers (VCSELs) and their potential applications in areas such as disinfection and medical therapy. This includes our demonstration of the shortest wavelength VCSEL, emitting at 310 nm under optical pumping, and a detailed analysis of its filamentary lasing characteristics. The UVB-emitting AlGaN-based VCSEL was realized by substrate removal using electrochemical etching, enabling the use of two high-reflectivity dielectric distributed Bragg reflectors. The potential of using this or alternative methods to push the emission to shorter wavelengths will be examined as well as concepts to realize electrically injected devices.
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| 122. |
- Hjort, Filip, 1991, et al.
(författare)
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Optical microprism cavities based on dislocation-free GaN
- 2020
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 117:23
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional growth of nanostructures can be used to reduce the threading dislocation density that degrades III-nitride laser performance. Here, nanowire-based hexagonal GaN microprisms with flat top and bottom c-facets are embedded between two dielectric distributed Bragg reflectors to create dislocation-free vertical optical cavities. The cavities are electron beam pumped, and the quality (Q) factor is deduced from the cavity-filtered yellow luminescence. The Q factor is similar to 500 for a 1000nm wide prism cavity and only similar to 60 for a 600nm wide cavity, showing the strong decrease in Q factor when diffraction losses become dominant. Measured Q factors are in good agreement with those obtained from quasi-3D finite element frequency-domain method and 3D beam propagation method simulations. Simulations further predict that a prism cavity with a 1000nm width will have a Q factor of around 2000 in the blue spectral regime, which would be the target regime for real devices. These results demonstrate the potential of GaN prisms as a scalable platform for realizing small footprint lasers with low threshold currents.
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| 123. |
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| 124. |
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| 125. |
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| 126. |
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| 127. |
- Ingham, J.D., et al.
(författare)
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32 Gb/s multilevel modulation of an 850 nm VCSEL for next-generation datacommunication standards
- 2011
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Ingår i: 2011 Conference on Lasers and Electro-Optics, CLEO 2011; Baltimore, MD; 1 May 2011 through 6 May 2011. - Washington, D.C. : OSA. - 2162-2701. - 9781557529107
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Konferensbidrag (refereegranskat)abstract
- An 850 nm vertical-cavity surface-emitting laser is modulated at 32 Gb/s using pulseamplitude modulation with four levels. Transmitter predistortion generates an optimized modulation waveform, which requires a receiver bandwidth of only 15 GHz.
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| 128. |
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| 129. |
- Jahed, Mehdi, 1988, et al.
(författare)
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Monolithic Multi-Wavelength VCSEL Arrays with Uniform Performance by Intra-Cavity Phase Tuning
- 2021
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Ingår i: Conference Digest - IEEE International Semiconductor Laser Conference. - 0899-9406.
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Konferensbidrag (refereegranskat)abstract
- We demonstrate monolithic multi-wavelength VCSEL arrays with wavelengths set by intra-cavity phase tuning. Precise channel spacing is achieved by Ar-ion etching. Uniform performance over an array is achieved by spectral matching and balancing of wavelength dependent gain, DBR reflectances and optical confinement factor.
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| 130. |
- Jahed, Mehdi, 1988, et al.
(författare)
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Precise setting of micro-cavity resonance wavelength by dry etching
- 2019
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Ingår i: Journal of Vacuum Science and Technology B: Nanotechnology and Microelectronics. - : American Vacuum Society. - 2166-2754 .- 2166-2746. ; 37:3
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Tidskriftsartikel (refereegranskat)abstract
- With an intracavity phase tuning technique, the authors demonstrate <2 nm precision in wavelength setting of vertical-cavity surface-emitting laser (VCSEL) microresonators in the wavelength range 1040-1070 nm using an Ar ion-beam etching process with subnanometer precision in etch depth. This postgrowth fabrication technique for controlling the wavelength of individual VCSELs is promising for the development of monolithic multiwavelength VCSEL arrays with precisely defined wavelengths for wavelength division multiplexed (WDM) optical interconnects and the assembly of compact and high-capacity WDM transmitters.
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