| 1. |
- Davani, Hooman A., et al.
(författare)
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Polarization investigation of a tunable high-speed short-wavelength bulk-micromachined MEMS-VCSEL
- 2012
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819489197 ; 8276, s. Art. no. 82760T-
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Konferensbidrag (refereegranskat)abstract
- We report the investigation of the state of polarization (SOP) of a tunable vertical-cavity surface-emitting laser (VCSEL) operating near 850 nm with a mode-hop free single-mode tuning range of about 12 nm and an amplitude modulation bandwidth of about 5 GHz. In addition, the effect of a sub-wavelength grating on the device and its influence on the polarization stability and polarization switching has been investigated. The VCSEL with an integrated sub-wavelength grating shows a stable SOP with a polarization mode suppression ratio (PMSR) more than 35 dB during the tuning.
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| 2. |
- Fuchs, Christian, et al.
(författare)
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Spatio-temporal turn-on dynamics of grating relief VCSELs
- 2007
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Ingår i: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 43:11-12, s. 1227-1234
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Tidskriftsartikel (refereegranskat)abstract
- Within a joint collaboration between modeling, technology and experiments, we investigate the polarization-resolved spatial emission and turn-on dynamics of oxide-confined vertical-cavity surface-emitting lasers with an integrated surface-relief grating. By applying a time-resolved imaging technique we demonstrate that the introduced high dichroism also maintains its influence dynamically. This leads to highly polarization-stable spatially fundamental Gaussian mode emission on 100-ps timescale. Finally, the achieved progress, but also the limits of this promising stabilization scheme are discussed.
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| 3. |
- Gierl, Christian, et al.
(författare)
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Tuneable VCSEL aiming for the application in interconnects and short haul systems
- 2011
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819484963 ; 7959
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Widely tunable vertical cavity surface emitting lasers (VCSEL) are of high interest for optical communications, gas spectroscopy and fiber-Bragg-grating measurements. In this paper we present tunable VCSEL operating at wavelength around 850 nm and 1550 nm with tuning ranges up to 20 nm and 76 nm respectively. The first versions of VCSEL operating at 1550 nm with 76 nm tuning range and an output power of 1.3mW were not designed for high speed modulation, but for applications where only stable continious tuning is essential (e.g. gas sensing). The next step was the design of non tunable VCSEL showing high speed modulation frequencies of 10 GHz with side mode supression ratios beyond 50 dB. The latest version of these devices show record output powers of 6.7mW at 20 °C and 3mW at 80 °C. The emphasis of our present and future work lies on the combination of both technologies. The tunable VCSEL operating in the 850 nm-region reaches a modulation bandwidth of 5.5GHz with an output power of 0.8mW.
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| 4. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Integrated MEMS-tunable VCSELs for reconfigurable optical interconnects
- 2012
-
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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| 5. |
- 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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| 6. |
- 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
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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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| 7. |
- Kögel, Benjamin, 1979, et al.
(författare)
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Singlemode tunable VCSELs with integrated MEMS technology
- 2011
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Ingår i: European Conference on Laser and Electro-Optics (CLEO/Europe).
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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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| 8. |
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