1. |
- Chitica, N, et al.
(author)
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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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In: Physica scripta. T. - : ROYAL SWEDISH ACAD SCIENCES. - 0281-1847. ; T79, s. 131-134
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Journal article (peer-reviewed)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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2. |
- Salomonsson, F., et al.
(author)
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Wafer fused p-InP/p-GaAs heterojunctions
- 1998
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In: Journal of Applied Physics. - 0021-8979 .- 1089-7550. ; 83:2, s. 768-774
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Journal article (peer-reviewed)abstract
- This article reports on the fabrication and characterization of wafer fused heterojunctions between p-InP and p-GaAs. Secondary ion mass spectroscopy was used to characterize doping profiles across the interface as well as the interface contamination with oxygen or carbon. The crystalline quality of the fused material was characterized using cross section and plan-view transmission electron microscopy. The electrical properties of the fused interface were studied as a function of various doping elements such as Be and Zn in InP or Zn and C in GaAs as well as for different acceptor concentrations in GaAs. Finally, the electrical characteristics were analyzed using a numerical model that includes thermionic emission and tunneling across the heterobarrier. © 1998 American Institute of Physics.
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3. |
- Streubel, K., et al.
(author)
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Long wavelength vertical cavity lasers
- 1999
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In: Proceedings of SPIE - The International Society for Optical Engineering. - San Jose, CA, USA. ; 3625:Bellingham, WA, United States, s. 304-314
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Journal article (peer-reviewed)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.
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4. |
- Streubel, K., et al.
(author)
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Novel technologies for 1.55-mu m vertical cavity lasers
- 2000
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In: Optical Engineering. - : SPIE-Intl Soc Optical Eng. - 0091-3286 .- 1560-2303. ; 39:2, s. 488-497
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Journal article (peer-reviewed)abstract
- We report on three novel vertical-cavity laser (VCL) structures for 1.55-mu m operation. Two of the structures utilize an n-type GalnAsP/InP Bragg mirror combined with an Al(Ga)As/GaAs mirror using either wafer fusion or metamorphic epitaxial growth. The third employs two wafer-fused AlGaAs/GaAs mirrors, in which lateral current confinement is obtained by localized fusion of the p mirror. Ali three VCLs use strained GalnAsP quantum welts as active material and achieve continuous-wave (cw) operation at room temperature or above. The single fused VCL operates up to 17 and 101 degrees C in continuous-wave and pulsed mode, respectively. The monolithic VCL-structure with a metamorphic GaAs/AlAs n-type mirror uses a reverse-biased tunnel junction for current injection. This laser achieves record high output power (1 mW) at room temperature and operates cw up to 45 degrees C. The double fused VCLs with a 10x10-mu m(2) active area operate cw up to 30 degrees C with threshold current as low as 2.5 mA and series resistance of 30 Omega. The emission spectra exhibit a single lasing mode polarized with 30-dB extinction ratio and a spectral linewidth of 150 MHz.
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5. |
- Bentell, J., et al.
(author)
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Characterisation of n-InP/n-GaAs Wafer Fused Heterojunctions
- 1999
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In: Physica scripta. T. - 0281-1847. ; 79, s. 206-208
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Journal article (peer-reviewed)abstract
- We have investigated the properties of wafer-fused Si-doped isotype hetero-junctions between GaAs and InP. Current/voltage measurements were conducted to study the influence of the doping concentrations on each side of the interface on the electrical conductivity. An almost ohmic behavior with a very low series resistance was obtained for the highest examined doping level on the GaAs side, whereas the doping concentration on the InP side was found to be of little significance. Fusion at different temperatures showed that the conductivity degrades significantly below 500°C, although mechanically stable junctions were obtained also at temperatures as low as 305°C. Secondary ion mass spectroscopy measurements showed no redistribution of Si, but indicated the presence of small amounts of C and Fe impurities at the interface.
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6. |
- Hammar, M., et al.
(author)
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Systematics of electrical conductivity across InP to GaAs wafer fused interfaces
- 1998
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In: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Tsukuba, Jpn. ; , s. 801-804
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Conference paper (peer-reviewed)abstract
- We report on the electrical and compositional characterization of wafer fused isotype heterojunctions between Zn, C or Si doped GaAs and Zn or Si doped InP. The junctions were characterized with current-voltage and secondary ion mass spectrometry (SIMS) measurements. It is demonstrated that very low-resistive junctions can be obtained in each case, but also that there is a strong influence from the detailed sample structure and processing conditions. SIMS was used to monitor the doping concentration across the interface as well as the impurity concentration of oxygen, carbon and iron.
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7. |
- Hammar, M., et al.
(author)
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Systematics of electrical conductivity across InP to GaAs wafer-fused interfaces
- 1999
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In: Japanese Journal of Applied Physics. - 0021-4922 .- 1347-4065. ; 38:2 B, s. 1111-1114
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Journal article (peer-reviewed)abstract
- We report on the electrical and compositional characterization of wafer-fused isotype heterojunctions between Zn-, C- or Si-doped GaAs and Zn- or Si-doped InP. The junctions were characterized by current-voltage and secondary ion mass spectrometry (SIMS) measurements. It is demonstrated that very low-resistive junctions can be obtained in each case, but also that there is a strong influence from the detailed sample structure and processing conditions. SIMS was used to monitor the doping concentration across the interface as well as the impurity concentrations of oxygen, carbon and iron. © 1999 Publication Board, Japanese Journal of Applied Physics.
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8. |
- Rapp, S., et al.
(author)
-
All-epitaxial single-fused 1.55 ÎŒm vertical cavity laser based on an InP bragg reflector
- 1999
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In: Japanese Journal of Applied Physics. - 0021-4922 .- 1347-4065. ; 38:2 B, s. 1261-1264
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Journal article (peer-reviewed)abstract
- We have realised an all-epitaxial 1.55 Όm vertical cavity laser by employing a single wafer-fusion step. The laser structure is fabricated by fusing a 32-period p-doped (C) AlGaAs/GaAs top mirror onto a half-cavity structure consisting of a 50-period n-doped (Si) GaInAsP/InP bottom mirror and a 9 quantum well GaInAsP-active material. Laser mesas are fabricated using a wet etching procedure for the top mirror. The top mirror also contains an AlAs layer for oxidation for current confinement. The lasers operate pulsed at temperatures up to 40°C and at pulse lengths of 10 Όs up to 5°C. The minimum threshold current density at room temperature is 1.8 kA/cm2 for a device diameter of 55 Όm. Compared to nonoxidised laser diodes, the threshold current is markedly decreased in oxidised laser diodes. © 1999 Publication Board, Japanese Journal of Applied Physics.
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9. |
- Rapp, S., et al.
(author)
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All epitaxial single-fused 1.55ÎŒm vertical cavity laser based on an InP Bragg reflector
- 1998
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In: Conference Proceedings - International Conference on Indium Phosphide and Related Materials. - Tsukuba, Jpn. ; , s. 303-306
-
Conference paper (peer-reviewed)abstract
- We have realised all epitaxial 1.55Όm vertical cavity lasers by employing a single wafer-fusion step. The laser structure is fabricated by fusing a 32 period p-doped (C) AlGaAs/GaAs top mirror to a half cavity structure consisting of a 50 period n-doped (Si) GaInAsP/InP bottom mirror and 9QW GaInAsP-active material. Laser mesas are fabricated using a wet etching procedure for the top mirror. The top mirror also contains an AlAs layer for oxidation for current confinement. The lasers operate pulsed for temperatures up to 40°C and at pulse lengths of 10Όs up to 5°C. The minimum threshold current density at room temperature is 1.8kA/cm2 for a device diameter of 55Όm. Compared to non-oxidised laser diodes, the oxidation decreases the threshold currents significantly.
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10. |
- Rapp, S., et al.
(author)
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Near room-temperature continuous-wave operation of electrically pumped 1.55 ÎŒm vertical cavity lasers with InGaAsP/InP bottom mirror
- 1999
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In: Electronics Letters. - 0013-5194 .- 1350-911X. ; 35:1, s. 49-50
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Journal article (peer-reviewed)abstract
- The first near room-temperature continuous-wave (CW) operation of a vertical cavity laser based on an epitaxial InGaAsP/InP bottom mirror is reported. The structure employs a package of nine strain compensated GaInAsP quantum wells and a wafer-fused GaAs/AlGaAs top mirror. For a 10 Όm diameter device, the threshold current is 6mA and the input threshold power is 21mW. The maximum operating temperature is 17 and 101°C for CW and pulsed conditions, respectively. © IEE 1999.
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