| 1. |
- Kopp, C., et al.
(författare)
-
Very compact FTTH Diplexer design using advanced wafer level fabrication methods
- 2008
-
Ingår i: MICRO-OPTICS 2008. - Strasbourg : SPIE.
-
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.
|
|
| 2. |
- Göthelid, M., et al.
(författare)
-
Sn-induced surface reconstructions on the Ge(111) surface studied with scanning tunneling microscopy
- 1992
-
Ingår i: Surface Science. - 0039-6028. ; 271:3, s. L357-L361
-
Tidskriftsartikel (refereegranskat)abstract
- Scanning tunneling microscopy (STM) has been used to study different Sn induced reconstructions on the Ge(111) surface; namely the (7 × 7), (5 × 5) and ( 3 × 3) R30° structures. The first two have been confirmed to be of the dimer adatom stacking faults (DAS) type with adatoms mainly being Sn. The ( 3 × 3)R30° superstructure was found at different Sn depositions. At 0.4 monolayer (ML) Sn coverage a homogeneous Sn adatom layer is adsorbed on the(1 × 1) surface in threefold sites directly over second-layer atoms (T4), while at low coverage, 0.1 ML, the top layer is a mixture of Sn and Ge atoms. We also propose the chemical identities of the different atoms seen in the STM images as related to their apparent height. © 1992.
|
|
| 3. |
- Mogg, S., et al.
(författare)
-
n-type doping induced losses in 1.3/1.55 ÎŒm distributed Bragg reflectors
- 2000
-
Ingår i: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Williamsburg, VA, USA. ; , s. 388-391
-
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.
|
|
| 4. |
- Streubel, K., et al.
(författare)
-
Long wavelength vertical cavity lasers
- 1999
-
Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - San Jose, CA, USA. ; 3625:Bellingham, WA, United States, s. 304-314
-
Tidskriftsartikel (refereegranskat)abstract
- We report on three novel vertical cavity laser (VCL) structures for 1.55 Όm operation. Two of the VCL structures utilize an n-type GaInAsP/InP Bragg mirror combined with an Al(Ga)As/GaAs mirror using either wafer-fusion or metamorphic epitaxial growth. The third VCL employs two wafer fused AlGaAs/GaAs mirrors, in which lateral current confinement is obtained by localized fusion of the p-mirror. All three VCLs use strained GaInAsP quantum wells as active material and achieve continuous-wave (CW) operation at room-temperature or above. The single fused VCL operates up to 17 °C and 101 °C in continuous-wave and pulsed mode, respectively. The monolithic VCL-structure with a metamorphic GaAs/AlAs n-type mirror uses a reversed biased tunnel junction for current injection. This laser achieves record high output power (1mW) at room temperature and operates CW up to 45 °C. The double fused VCLs with a 10×10 Όm2 active area operate CW up to 30 °C with threshold current as low as 2.5 mA and series resistance of 30 Ohms. The emission spectra exhibit a single lasing mode polarized with 30 dB extinction ratio and a spectral linewidth of 150 MHz.
|
|
| 5. |
- Törnevik, C., et al.
(författare)
-
Adsorption of Sn onSi(111)7 × 7 : reconstructions in the monolayer regime
- 1994
-
Ingår i: Surface Science. - 0039-6028. ; 314:2, s. 179-187
-
Tidskriftsartikel (refereegranskat)abstract
- Different monolayer phases of Sn on Si(111)7 × 7 have been studied by means of scanning tunneling microscopy (STM), core-level photoelectron spectroscopy (XPS), and Rutherford backscattering spectrometry (RBS). The STM results show that 3 × 3 reconstructions are obtained for room-temperature deposition of 1 3 ML of Sn followed by sample annealing in a broad temperature range. A T4 Sn adatom 3 ×3 phase is formed for temperatures between 500 and 800°C, with a concentration of defects that is strongly dependent on the temperature and which is as high as 25% for the lowest temperatures. Above 825°C a second 3×3 adatom reconstruction is formed, a mosaic-like phase with a 1:1 mixture of Si and Sn atoms in T4 positions. The results from investigations of the higher coverage 2 3 × 2 3 reconstruction by XPS and RBS support the theory that this phase is a two-layer epitaxial Sn structure with all Si(111) dangling bonds saturated. The Sn coverage for this phase was determined to be between 1 and 1.2 ML. © 1994.
|
|
| 6. |
- Törnevik, C., et al.
(författare)
-
Epitaxial growth of Sn on Si(111) : A direct atomic-structure determination of the (2 √3 ×2 √3) R30° reconstructed surface
- 1991
-
Ingår i: Physical Review B. - 0163-1829. ; 44:23, s. 13144-13147
-
Tidskriftsartikel (refereegranskat)abstract
- Scanning tunneling microscopy (STM) has been used to determine the surface atomic structure of Si(111)(23 ×2 3) -Sn. The topographic images show four resolved atoms in each (2 3 ×2 3) unit cell, and the structure is found to be onefold symmetric. Together with coverage measurements, the STM analysis implies that the reconstructed surface is an epitaxial Sn two-layer structure, where the atoms adopt a bonding configuration characteristic of -Sn. A three-dimensional structure model, in accordance with the obtained results, is proposed. © 1991 The American Physical Society.
|
|
| 7. |
- Wigren, C., et al.
(författare)
-
Sm- and Yb-induced reconstructions of the Si(111) surface
- 1993
-
Ingår i: Physical Review B. - 0163-1829. ; 48:15, s. 11014-11019
-
Tidskriftsartikel (refereegranskat)abstract
- Low-energy electron diffraction, scanning tunneling microscopy, and photoelectron spectroscopy results from the submonolayer Sm- and Yb-induced surface structures are presented. Several similar metal-induced surface reconstructions are found to exist for Yb and Sm on Si(111) for low submonolayer coverages: 3×2, 5×1, and 7×1. At higher submonolayer coverage, Yb induces a 2×1 reconstruction while Sm induces a (3 × 3) R30°-like reconstruction. Yb is found to be divalent in all structures, whereas the Sm valence increases with increasing coverage. In the 3×2 structure only divalent Sm is present, in the 5×1 and 7×1 structures a small amount of trivalent Sm appears, and, finally, in the (3 × 3) R30°structure approximately half of the Sm atoms are trivalent. The surface Fermi-level position in the band gap for the different Sm and Yb reconstructions has been measured. The difference in valence stability between Sm and Yb is suggested to be the cause of the difference in the high-coverage structures found and the differences in pinning level for the two elements observed for the 5×1 and 7×1 structures. © 1993 The American Physical Society.
|
|
| 8. |
- Zwiller, V., et al.
(författare)
-
Studies of self-assembled InP quantum dots in planar microcavities
- 2000
-
Ingår i: Materials Science and Engineering B: Solid-State Materials for Advanced Technology. - Strasbourg, France. ; 69:Lausanne, Switzerland, s. 314-317
-
Tidskriftsartikel (refereegranskat)abstract
- Self-assembled InP quantum dots have been grown in planar microcavities. The dots were embedded in a Ga0.52In0.48P spacer grown on top of a high reflectance epitaxial Al0.29Ga0.71As/AlAs distributed Bragg reflector (DBR) to obtain a 33λ/4 cavity. The Fabry-Perot microcavity is formed between the AlGaAs/AlAs DBR and a dielectric SiNx/SiO2 DBR deposited on top of the GaInP spacer. The quantum dot emission is centered at 1.62 eV at 7 K. The microcavity resonance is centered at 1.65 eV, with a linewidth of 2 meV. Micro-photoluminescence (PL) studies using different objectives with different numerical apertures enable the collection of transversal modes.
|
|
