| 141. |
- Kumari, Sulakshna, et al.
(författare)
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Design of an 845-nm GaAs Vertical-Cavity Silicon-Integrated Laser with an Intracavity Grating for Coupling to a SiN Waveguide Circuit
- 2017
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Ingår i: IEEE Photonics Journal. - 1943-0655. ; 9:4, s. 1504109-
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Tidskriftsartikel (refereegranskat)abstract
- A short-wavelength hybrid GaAs vertical-cavity silicon-integrated laser (VCSIL) with in-plane waveguide coupling has been designed and optimized using numerical simulations. A shallow etched silicon nitride (SiN) grating is placed inside the cavity of the hybrid vertical-cavity silicon-integrated laser to both set the polarization state of the resonant optical field and to enable output coupling to a SiN waveguide with high efficiency. The numerical simulations predict that for apertures of 4 and 6-μm oxide-confined VCSILs operating at 845-nm wavelength, a slope efficiency for the light coupled to the waveguide of 0.18 and 0.22 mW/mA is achievable, respectively, while maintaining a low threshold gain of 583 and 589 cm−1, respectively, for the lasing.
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| 142. |
- Kumari, Sulakshna, et al.
(författare)
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Integration of GaAs-based VCSEL array on SiN platform with HCG reflectors for WDM applications
- 2015
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9781628414622 ; 9372, s. Art. no. 93720U-
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Konferensbidrag (refereegranskat)abstract
- We present a GaAs-based VCSEL structure, BCB bonded to a Si3N4 waveguide circuit, where one DBR is substituted by a free-standing Si3N4 high-contrast-grating (HCG) reflector realized in the Si3N4 waveguide layer. This design enables solutions for on-chip spectroscopic sensing, and the dense integration of 850-nm WDM data communication transmitters where individual channel wavelengths are set by varying the HCG parameters. RCWA shows that a 300nm-thick Si3N4 HCG with 800nm period and 40% duty cycle reflects strongly (
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| 143. |
- Kumari, Sulakshna, et al.
(författare)
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Vertical-Cavity Silicon-Integrated Laser with In-Plane Waveguide Emission at 850 nm
- 2018
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Ingår i: Laser and Photonics Reviews. - : Wiley. - 1863-8899 .- 1863-8880. ; 12:2, s. 1700206-
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Tidskriftsartikel (refereegranskat)abstract
- A continuous-wave electrically-pumped short-wavelength hybrid vertical-cavity silicon-integrated laser (VCSIL) with in-plane emission into a silicon nitride (SiN) waveguide is experimentally demonstrated. The coupling from the vertical cavity into the in-plane SiN waveguide is achieved by a weak grating on the SiN waveguide placed inside the cavity. The grating provides coupling, sets the polarization of the lasing output, and provides transverse mode control. A 5 mu m oxide-aperture diameter device with a threshold current of 1.1 mA produces 73 mu W single-sided waveguide-coupled optical output power at 2.6 mA bias current at a wavelength of 856 nm and a side-mode suppression ratio (SMSR) of 29 dB.
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| 144. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Integrated MEMS-tunable VCSELs for reconfigurable optical interconnects
- 2012
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819489197 ; 8276, s. Article Number: 82760Q-
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Konferensbidrag (refereegranskat)abstract
- A simple and low-cost technology for tunable vertical-cavity surface-emitting lasers (VCSELs) with curved movable micromirror is presented. The micro-electro-mechanical system (MEMS) is integrated with the active optical component (so-called half-VCSEL) by means of surface-micromachining, using a reflown photoresist droplet as sacrificial layer. The technology is demonstrated for electrically pumped, short-wavelength (850nm) tunable VCSEts. Fabricated devices with 10 mu m oxide aperture are singlemode with sidemode suppression >35 dB, tunable over 24 mit with output power up to 0.5 mW, and have a beam divergence angle
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| 145. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Integrated MEMS-Tunable VCSELs Using a Self-Aligned Reflow Process
- 2012
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Ingår i: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 48:2, s. 144-152
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Tidskriftsartikel (refereegranskat)abstract
- A simple microelectromechanical systems technology for wafer-scale integration of tunable vertical-cavity surface-emitting lasers (VCSELs) is presented. The key element is a self-aligned reflow process to form photoresist droplets, which serve as sacrificial layer and preform for a curved micromirror. Using a 3-D electromagnetic model, the half-symmetric cavity is optimized for singlemode emission. The technology is demonstrated for electrically pumped, short-wavelength (850 nm) tunable VCSELs, but is transferable to other wavelengths and material systems. Fabricated devices with 10 mu m large current aperture are singlemode and tunable over 24 nm. An improved high-speed design with reduced parasitic capacitance enables direct modulation with 3dB-bandwidths up to 6 GHz and data transmission at 5Gbit/s. Small signal analysis shows that the intrinsic parameters (resonance frequency and damping) are wavelength dependent through the differential gain.
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| 146. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Integrated MEMS-tunable VCSELs with high modulation bandwidth
- 2011
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Ingår i: Electronics Letters. - : Institution of Engineering and Technology (IET). - 1350-911X .- 0013-5194. ; 47:13, s. 764-756
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Tidskriftsartikel (refereegranskat)abstract
- The modulation bandwidth of micromachined tunable VCSELs is typically limited by the parasitic capacitance associated with the large mesa platform for the movable mirror. Presented is a simple technology for wafer-scale integration of tunable VCSELs with low mesa capacitance and high modulation bandwidth. Small signal measurements show a 3dB bandwidth of up to 6 GHz over a tuning range of 18 nm. Digital modulation is demonstrated with error-free data transmission at 5 Gbit/s and eye diagrams at 10 Gbit/s.
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| 147. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Integrated Tunable VCSELs With Simple MEMS Technology
- 2010
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Ingår i: Semiconductor Laser Conference (ISLC), 2010 22nd IEEE International. - 0899-9406. - 9781424456833
-
Konferensbidrag (refereegranskat)abstract
- A simple MEMS technology for wafer-scale fabrication of tunable VCSELs is presented. Reflown photo-resist droplets serve as preform for making curved movable micro-mirrors. First devices show a tuning range of 15 nm with mW-output power.
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| 148. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Short-wavelength tunable VCSELs
- 2009
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Ingår i: European Semiconductor Laser Workshop (ESLW).
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 149. |
- Kögel, Benjamin, 1979, et al.
(författare)
-
Singlemode tunable VCSELs with integrated MEMS technology
- 2011
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Ingår i: European Conference on Laser and Electro-Optics (CLEO/Europe).
-
Konferensbidrag (refereegranskat)abstract
- A simple MEMS technology for wafer-scale integration of short-wavelength tunable VCSELs is presented. Using a 3D model the half-symmetric cavity is optimized for singlemode emission from 10 μm large apertures over 12 nm tuning range.
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| 150. |
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