| 1. |
- Kopp, C., et al.
(författare)
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Very compact FTTH Diplexer design using advanced wafer level fabrication methods
- 2008
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Ingår i: MICRO-OPTICS 2008. - Strasbourg : SPIE.
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Konferensbidrag (refereegranskat)abstract
- FTTH networks require implementing a diplexer at each user termination. According to most of the standards, this diplexer detects a download signal beam at 1.49ÎŒm and emits an upload signal beam at 1.31ÎŒm on the same single mode fibre. Both signals exhibit datarate speed below 2.5Gbps. Today, most of the diplexers are obtained by actively aligning a set of individual optoelectronic components and micro-optics. However, new manufacturing solutions satisfying very low cost and mass production capability requirements of this market would help to speed the massive spreading of this technology. In this paper, we present an original packaging design to manufacture Diplexer Optical Sub-Assembly for FTTH application. A dual photodiode is stacked over a VCSEL and detects both the download signal beam at 1.49ÎŒm passing through the laser and one part of the upload signal beam at 1.31ÎŒm for monitoring. To satisfy this approach, an innovative VCSEL has been designed to have a very high transmission at 1.49ÎŒm. All these components are mounted on a very small circuit board on glass including also integrated circuits such as transimpedance amplifier. So, the device combines advanced optoelectronic components and highly integrated Multi-Chip-Module on glass approach using collective wafer-level assembling technologies. For the single mode fibre optical coupling, active and passive alignment solutions are considered.
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| 2. |
- Asplund, C., et al.
(författare)
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Doping-induced losses in AlAs/GaAs distributed Bragg reflectors
- 2001
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 90:2, s. 794-800
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Tidskriftsartikel (refereegranskat)abstract
- We have studied n- and p-type doping-induced performance degradation of AlAs/GaAs distributed Bragg reflectors (DBRs) for applications in vertical cavity lasers (VCLs). Based on high-accuracy optical reflectance and triple-axis x-ray diffraction measurements on a variety of differently doped DBR structures grown by metalorganic vapor-phase epitaxy, a fitting procedure was employed to extract the doping-dependent optical loss. A striking observation is that the reflectance of these DBRs is much more sensitive to n- than p-type doping incorporation. While in the latter case the loss can be well accounted for by intervalence-band and free-carrier absorption, additional loss mechanisms must be considered for n-type DBRs. We relate the losses to doping-enhanced interdiffusion effects resulting in increased interface scattering. These findings should have important consequences for the design of VCLs, demonstrating the importance of reduced n-type doping concentrations and/or growth temperatures, or the application of alternative device concepts, e.g., employing intracavity contacts.
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| 3. |
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| 4. |
- Chitica, N, et al.
(författare)
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Fabrication of tunable InP/air-gap Fabry-Perot cavities by selective etching of InGaAs sacrificial layers
- 1999
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Ingår i: Physica scripta. T. - : ROYAL SWEDISH ACAD SCIENCES. - 0281-1847. ; T79, s. 131-134
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Tidskriftsartikel (refereegranskat)abstract
- We report the fabrication of InP/air-gap Fabry-Perot resonant cavities with an improved tunability characteristic achieved through the micromachining of more flexible suspended InP beams. The micromechanical structures are electrostatically actuated. A tuning range of 55 nm is demonstrated for an actuation voltage of 12 V. The low leakage current, of less than 10 µA for a bias of up to 30 V, provides a low actuation power. The tunable air-gap cavities are fabricated by selective wet etching of InGaAs sacrificial layers. An FeCl3 based etchant is used to completely remove the InGaAs material without affecting the thickness of the InP layer. The anisotropy of the etch rate of InGaAs was also investigated and exploited in the micromachining process.
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| 5. |
- Creek, S, et al.
(författare)
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Deflection of surface-micromachined devices due to internal, homogeneous or gradient stresses
- 1999
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Ingår i: SENSORS AND ACTUATORS A-PHYSICAL. - : ELSEVIER SCIENCE SA. - 0924-4247. ; 78:1, s. 1-7
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Devices surface-micromachined out of a thin film containing an internal stress will be deformed upon release. The stress of a film can be approximated in second order by a biaxial homogeneous stress superimposed on a linear biaxial stress gradient. In ord
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| 6. |
- Hammar, Mattias, et al.
(författare)
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1.3-mu m InGaAs vertical-cavity surface-emitting lasers
- 2005
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Ingår i: 2005 IEEE LEOS Annual Meeting Conference Proceedings (LEOS). - 0780392175 ; , s. 396-397
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Konferensbidrag (refereegranskat)abstract
- We report on the fabrication and performance of N-free InGaAs/GaAs 1.3-mu m range vertical-cavity surface-emitting lasers (VCSELs). Using optimized quantum-well (QW) growth conditions in combination with negative gain-cavity tuning, high-performance VCSELs with emission wavelength up to 1300 nm are realized. The performance figures include mA-range threshold currents, mW-range singlemode output power, continuous-wave operation up to 140 degrees C and 10 Gbit/s data transmission.
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| 7. |
- Mogg, S., et al.
(författare)
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Absolute reflectance measurements by a modified cavity phase-shift method
- 2002
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 73:4, s. 1697-1701
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Tidskriftsartikel (refereegranskat)abstract
- This article reports on a modified cavity phase-shift (CAPS) method for accurate and reliable characterization of high reflectance mirrors. Our approach relies on using a directly modulated Fabry-Perot laser to circumvent the difficulties encountered in previous attempts with the CAPS method. The Fabry-Perot laser diode ensures a constant coupling between the probe laser and test cavity modes. This results in a stable beam intensity transmitted through the test cavity allowing for accurate measurements of the phase shift from which the absolute reflectance can be determined. The experimental arrangement presented in this article is versatile and easy to use. The method is nondestructive and especially suited for the characterization of distributed Bragg reflectors (DBRs) employed in vertical-cavity optoelectronic devices. A premium feature of this method is its capability to probe a relatively small area of less than 1 mm which can be positioned anywhere across the surface of the wafer. We demonstrate the use of the method by measuring the absolute reflectance of metalorganic vapor-phase epitaxy grown AlAs/GaAs DBRs for 1.3 mum vertical-cavity lasers.
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| 8. |
- Mogg, S., et al.
(författare)
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n-type doping induced losses in 1.3/1.55 ÎŒm distributed Bragg reflectors
- 2000
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Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Williamsburg, VA, USA. ; , s. 388-391
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Tidskriftsartikel (refereegranskat)abstract
- The effect of n-type doping on the peak reflectivity of InGaAsP/InP as well as GaAs/AlAs distributed Bragg reflectors for long-wavelength vertical-cavity lasers has been investigated. A variety of mirrors with different doping levels were grown in both material systems using metal organic vapour phase epitaxy. The reflectance of the structures was measured with high accuracy employing two independent measurement techniques. While nominally undoped DBRs exhibit an expected reflectivity in excess of 99.9%, doping is found to induce significant losses resulting in up to 0.6% reduced reflectance.
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| 9. |
- Mogg, S., et al.
(författare)
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Properties of highly strained InGaAs/GaAs quantum wells for 1.2-mu m laser diodes
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 81:13, s. 2334-2336
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Tidskriftsartikel (refereegranskat)abstract
- The properties of 1.2-mum highly strained InGaAs quantum wells (QWs) grown on GaAs substrates have been analyzed. Optical gain spectra versus injection current and temperature, transparency current density, as well as other figures of merit were assessed from measurements on broad-area and ridge-waveguide lasers based on these QWs. Such active regions are of interest for a range of applications, including GaAs-based high-power lasers and vertical-cavity lasers for wavelengths beyond 1.2 mum.
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| 10. |
- Strassner, M, et al.
(författare)
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III-V semiconductor material for tunable Fabry-Perot filters for coarse and dense WDM systems
- 2000
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Ingår i: SENSORS AND ACTUATORS A-PHYSICAL. - : ELSEVIER SCIENCE SA. - 0924-4247. ; 85:1-3, s. 249-255
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Tidskriftsartikel (refereegranskat)abstract
- In the following payer, we report on the investigation of the mechanical properties of InP grown on InGaAs by organic metal vapor phase epitaxy (OMVPE). When InP is grown, it is stressed due to an unintentional arsenic doping profile. This stress gradient
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