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| 2. |
- Tångring, Ivar, 1978, et al.
(författare)
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1.58 µm InGaAs quantum well laser on GaAs
- 2007
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Ingår i: Applied Physics Letters. ; 91, s. 221101-
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the 1.58 µm emission at room temperature from a metamorphic In0.6Ga0.4As quantum well laser grown on GaAs by molecular beam epitaxy. The large lattice mismatch was accommodated through growth of a linearly graded buffer layer to create a high quality virtual In0.32Ga0.68As substrate. Careful growth optimization ensured good optical and structural qualities. For a 1250×50 µm2 broad area laser, a minimum threshold current density of 490 A/cm2 was achieved under pulsed operation. This result indicates that metamorphic InGaAs quantum wells can be an alternative approach for 1.55 µm GaAs-based lasers.
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| 3. |
- Tångring, Ivar, 1978, et al.
(författare)
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Molecular beam epitaxy growth of A 1.58 μm InGaAs quantum well laser on GaAs
- 2008
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - 1092-8669. - 9781424422593
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Konferensbidrag (refereegranskat)abstract
- We demonstrate how MBE growth parameters can be optimized to produce a metamorphic InGaAs QW laser emitting in the 1.55 ?m range. Different techniques to suppress roughening while maintaining low threading dislocation densities are evaluated. Finally, we demonstrate a 50×1250 ?m 2 broad area FabryPerot laser that produces pulsed lasing with a threshold current density of 490 A/cm2 and a wavelength of 1.58 ?m at room temperature.
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| 5. |
- Lambert, A., et al.
(författare)
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Validation of the Aura Microwave Limb Sounder middle atmosphere water vapor and nitrous oxide measurements
- 2007
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 112:D24
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Tidskriftsartikel (refereegranskat)abstract
- The quality of the version 2.2 (v2.2) middle atmosphere water vapor and nitrous oxide measurements from the Microwave Limb Sounder (MLS) on the Earth Observing System (EOS) Aura satellite is assessed. The impacts of the various sources of systematic error are estimated by a comprehensive set of retrieval simulations. Comparisons with correlative data sets from ground-based, balloon and satellite platforms operating in the UV/ visible, infrared and microwave regions of the spectrum are performed. Precision estimates are also validated, and recommendations are given on the data usage. The v2.2 H 2 O data have been improved over v1.5 by providing higher vertical resolution in the lower stratosphere and better precision above the stratopause. The single-profile precision is ∼0.2-0.3 ppmv (4-9%), and the vertical resolution is ∼3-4 km in the stratosphere. The precision and vertical resolution become worse with increasing height above the stratopause. Over the pressure range 0.1-0.01 hPa the precision degrades from 0.4 to 1.1 ppmv (6-34%), and the vertical resolution degrades to ∼12-16 km. The accuracy is estimated to be 0.2-0.5 ppmv (4-11%) for the pressure range 68-0.01 hPa. The scientifically useful range of the H 2 O data is from 316 to 0.002 hPa, although only the 82-0.002 hPa pressure range is validated here. Substantial improvement has been achieved in the v2.2 N 2 O data over v1.5 by reducing a significant low bias in the stratosphere and eliminating unrealistically high biased mixing ratios in the polar regions. The single-profile precision is ∼13-25 ppbv (7-38%), the vertical resolution is ∼4-6 km and the accuracy is estimated to be 3-70 ppbv (9-25%) for the pressure range 100-4.6 hPa. The scientifically useful range of the N 2 O data is from 100 to 1 hPa. Copyright 2007 by the American Geophysical Union.
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| 6. |
- Wu, W.-C., et al.
(författare)
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60 GHz Broadband MS-to-CPW Hot-Via Flip Chip Interconnects
- 2007
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Ingår i: Microwave and Wireless Components Letters, IEEE. ; 17:11, Nov. 2007, s. 784-786
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Tidskriftsartikel (refereegranskat)abstract
- In this letter, the microstrip-to-coplanar waveguide(MS-to-CPW) hot-via flip chip interconnect has been experimentallydemonstrated to have broadband performance from dc to67 GHz. The interconnect structures with the hot-via transitions were first designed and optimized by using the electromagnetic simulation tool. Three types of designs were investigated in this letter. The interconnect structures were then fabricated and radio frequency (RF) tested up to 67 GHz. The optimized interconnectstructure with the compensation design demonstrated excellent RFcharacteristics with the insertion loss less than 0.5 dB and the returnloss below 18 dB over a very broad bandwidth from dc to67 GHz. This is to our
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| 7. |
- Wu, W. C., et al.
(författare)
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Coaxial transitions for CPW-to-CPW flip chip interconnects
- 2007
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Ingår i: Electronics Letters. ; 43:17, Aug. 16, s. 929-930
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Tidskriftsartikel (refereegranskat)abstract
- A novel coaxial transition for CPW-to-CPW flip chip interconnect ispresented and experimentally demonstrated. To realise the coaxialtransition on the CPW circuit, benzocyclobutene was used as theinterlayer dielectric between the vertical coaxial transition and theCPW circuit. The coaxial interconnect structure was successfullyfabricated and RF characterised to 67 GHz. The structure showedexcellent interconnect performance from DC up to 55 GHz with lowreturn loss below 20 dB and low insertion loss less
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| 8. |
- Wu, W. C., et al.
(författare)
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Design, Fabrication, and Characterization of Novel Vertical Coaxial Transitions for Flip-Chip Interconnects
- 2009
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Ingår i: IEEE Transactions on Advanced Packaging. - 1521-3323. ; 32:2, s. 362-371
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a novel transition design using vertical "coaxial transition" for coplanar waveguide (CPW-to-CPW) flip-chip interconnect is proposed and presented for the first time. The signal continuity is greatly improved since the coaxial-type transition provides more return current paths compared to the conventional transition in the flip-chip structure. The proposed coaxial transition structure shows a real coaxial property from the 3-D electromagnetic wave simulation results. The design rules for the coaxial transition are presented in detail with the key parameters of the coaxial transition structure discussed. For demonstration, the back-to-back flip-chip interconnect structures with the vertical coaxial transitions have been successfully fabricated and characterized. The demonstrated interconnect structure using the coaxial transition exhibits the return loss below 25 dB and the insertion loss within 0.4 dB from dc to 40 GHz. Furthermore, the measurement and simulation results show good agreement. The novel coaxial transition demonstrates excellent interconnect performance for flip-chip interconnects and shows great potential for flip-chip packaging applications at millimeter waves.
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| 9. |
- Tångring, Ivar, 1978, et al.
(författare)
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Metamorphic InGaAs telecom lasers on GaAs
- 2009
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. - 9780819474766 ; Proc. SPIE 7230, s. 723003-
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Konferensbidrag (refereegranskat)abstract
- We demonstrate GaAs-based metamorphic lasers in the 1.3-1.55 μm telecom range grown by molecular beam epitaxy.The introduction of dopants in a compositionally graded layer is shown to significantly influence material properties, aswell as having impact on the laser device design. Investigating and understanding of strain relaxation and dislocationdynamics is useful for improving material quality, performance and robustness of metamorphic devices. We demonstratepulsed lasing up to 1.58 μm and continuous wave lasing at 1.3 μm at room temperature with low threshold currents.
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| 10. |
- Wang, Shu Min, 1963, et al.
(författare)
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Metamorphic InGaAs Materials and Telecom Lasers
- 2009
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Ingår i: International Conference on Materials and Advanced Technology (ICMAT) 2009, Singapore, June 28 - July 3, 2009. (invited paper).
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Konferensbidrag (refereegranskat)
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