| 1. |
- Akram, Nadeem, 1971-, et al.
(författare)
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High-Speed Performance of 1.55 µm Buried Hetero-Structure Lasers with 20 InGaAsP/InGaAlAs Quantum-Wells
- 2006
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Ingår i: 2006 European Conference on Optical Communications Proceedings, ECOC 2006. - : IEEE. - 9782912328397 ; , s. 1-2
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Konferensbidrag (refereegranskat)abstract
- 1550 nm re-grown FP lasers having 20 InGaAsP/InGaAlAs strain-balanced QWs exhibit low threshold current density, high T0 (78.0 #x000B0;C) and high resonance frequency (24 GHz) indicating that a large number of shallow barrier QWs are attractive for un-cooled high-speed direct-modulation applications.
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| 2. |
- Angulo Barrios, C., et al.
(författare)
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GaAs/AlGaAs buried-heterostructure laser diodes with semi-insulating GaInP:Fe regrowth
- 2001
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Ingår i: Lasers and Electro-Optics, 2001. CLEO/Pacific Rim 2001. The 4th Pacific Rim Conference on.
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Konferensbidrag (refereegranskat)abstract
- GaAs/AlGaAs buried-heterostructure in-plane lasers and vertical-cavity surface-emitting lasers using GaInP:Fe as the burying layer have been fabricated and investigated. Regrowth of GaInP:Fe around etched laser mesas was achieved by hydride vapor phase epitaxy. The lasers exhibit good performance under CW operation and show promising high-speed characteristics.
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| 3. |
- Dhanabalan, D., et al.
(författare)
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Studies on Schottky Barrier Diodes Fabricated using Single-Crystal Wafers of β-Ga2O3 Grown by the Optical Floating Zone Technique
- 2022
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Ingår i: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951. ; 259:2
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Tidskriftsartikel (refereegranskat)abstract
- β-Ga2O3 is one of the most promising wide-bandgap materials for optoelectronic applications as well as a conducting substrate for GaN-based device technologies. Single crystals of undoped β-Ga2O3 are grown by the optical floating zone technique utilizing compressed dry air as growth atmosphere. The properties of β-Ga2O3 are highly anisotropic. Optimization of the processing recipe for wafers along different orientations suitable for device development is conducted. Structural, optical, and electrical properties of the wafers are determined. Efforts are made to fabricate Schottky diodes based on Pt/Ti/Au–β-Ga2O3–Ti/Au device structures. Devices are fabricated on (−201) cut wafers. The device characteristics are discussed in detail.
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| 4. |
- Gu, Tian, et al.
(författare)
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Hybrid Integrated Photonic Platforms : feature issue introduction
- 2021
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Ingår i: Optical Materials Express. - : The Optical Society. - 2159-3930 .- 2159-3930. ; 11:12, s. 4095-4096
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Hybrid photonic integration and interfaces allow different optical materials and components to be combined on a single platform and thus are crucial to future integrated photonic systems. This feature issue covers frontier research, technologies, and perspectives in this rapidly-evolving area and aims to address the key challenges and requirements across a broad range of photonic technologies.
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| 5. |
- Ha Ryu, Jae, et al.
(författare)
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Beam stability of buried-heterostructure quantum cascade lasers employing HVPE regrowth
- 2021
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087. ; 29:2, s. 2819-2826
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of beam stability for mid-infrared (IR)-emitting quantum cascade lasers (QCLs) are important for applications that require the beam to travel through air to remote targets, such as free-space communication links. We report beam-quality measurement results of narrow-ridge, 4.6 mu m-emitting buried-heterostructure (BH) QCLs fabricated using ICP etching and HVPE regrowth. Beam-quality measurements under QCW operation exhibit M-2 < 1.2 up to 1 W for similar to 5 mu m-wide ridges. 5 mu m-wide devices display some small degree of centroid motion with increasing output power (< 0.125 mrad), which corresponds to a targeting error of similar to 1.25 cm over a distance of 100 m.
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| 6. |
- Hammar, Mattias, 1961-, et al.
(författare)
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Compound Semiconductors
- 2021
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Ingår i: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951. ; 258:2
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Tidskriftsartikel (refereegranskat)
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| 7. |
- Hammar, Mattias, 1961-, et al.
(författare)
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Compound Semiconductors
- 2022
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Ingår i: Physica Status Solidi (a) applications and materials science. - : Wiley. - 1862-6300 .- 1862-6319. ; 219:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 8. |
- Han, Mengyao, et al.
(författare)
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High Spectral Efficiency Long-Wave Infrared Free-Space Optical Transmission With Multilevel Signals
- 2023
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 0733-8724 .- 1558-2213. ; 41:20, s. 6514-6520
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Tidskriftsartikel (refereegranskat)abstract
- This study explores the potential of long-wave infrared free-space optical (FSO) transmission that leverages multilevel signals to attain high spectral efficiency. The FSO transmission system consists of a directly modulated-quantum cascade laser (DM-QCL) operating at 9.15 mu m and a mercury cadmium telluride (MCT) detector. To fully understand the system, we conduct measurements on the DM-QCL chip and MCT detector and assess the overall amplitude response of the DM-QCL, MCT detector, and all electrical components. We apply various signals, including on-off keying (OOK), 4-level pulse amplitude modulation (PAM4), 6-level PAM (PAM6), and 8-level PAM (PAM8) to maximize the bit rate and spectral efficiency of the FSO transmission. Through a two-dimensional sweeping of the laser bias current and MCT detector photovoltage, we optimize the transmission performance. At the optimal operation point, the FSO system achieved impressive results which are up to 6 Gbaud OOK, 3.5 Gbaud PAM4, 3 Gbaud PAM6, and 2.7 Gbaud PAM8 signal transmissions, with a bit error rate performance below 6.25% overhead hard decision-forward error correction limit when the DM-QCL operates at 10 degrees C. We also evaluate the eye diagrams and stability of the system to showcase its remarkable transmission performance. Our findings suggest that the DM-QCL and MCT detector-based FSO transceivers offer a highly competitive solution for the next generation of optical wireless communication systems.
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| 9. |
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| 10. |
- Joharifar, Mahdieh, et al.
(författare)
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High-Speed 9.6-μm Long-Wave Infrared Free- Space Transmission with a Directly-Modulated QCL and a Fully-Passive QCD
- 2023
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Ingår i: Journal of Lightwave Technology. - : Institute of Electrical and Electronics Engineers Inc.. - 0733-8724 .- 1558-2213. ; 41:4, s. 1087-
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Tidskriftsartikel (refereegranskat)abstract
- Free-space optics (FSO) in the mid-infrared (mid- IR) contains rich spectral resources for future ultrahigh-speed wireless communications yet is currently under-exploited. Two atmospheric transmission windows at the mid-IR, namely, the mid-wave IR (MWIR, 3-5 µm) and the long-wave IR (LWIR, 8-12 µm), show great potential in supporting free-space communications for both terrestrial and space application scenarios. Particularly, the LWIR signal with a longer wavelength has high intrinsic robustness against aerosols' scattering and turbulence-induced scintillation and beam broadening effects, which are the main concerns hindering the wide deployment of practical FSO systems. In this context, high-bandwidth semiconductor-based mid-IR FSO transceivers will be desirable to meet the requirements of low energy consumption and small footprints for large-volume development and deployment. Quantum cascade devices, including quantum cascade lasers (QCLs) and quantum cascade detectors (QCDs), appear promising candidates to fulfill this role. In this work, we report a high-speed LWIR FSO transmission demonstration with a 9.6-µm directly-modulated (DM)-QCL and a fully passive QCD without any active cooling or bias voltage. Up to 8 Gb/s, 10 Gb/s, and 11 Gb/s signal transmissions are achieved when operating the DM- QCL at 10°C, 5°C, and 0°C, respectively. These results indicate a significant step towards an envisioned fully-connected mid-IR FSO solution empowered by the quantum cascade semiconductor devices.
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