![]() ; ; et al in Applied Physics Letters (2006), 88(4), 0411181-0411183 We have fabricated and characterized novel traveling-wave photomixers with recessed interdigitated metal-semiconductor-metal MSM contacts based on low-temperature-grown GaAs. The new recessed MSM geometry ... [more ▼] We have fabricated and characterized novel traveling-wave photomixers with recessed interdigitated metal-semiconductor-metal MSM contacts based on low-temperature-grown GaAs. The new recessed MSM geometry led to an improved electric-field distribution inside the photomixer structure and resulted in an up-to-100% increase in the output power of continuously operated devices, compared to conventional MSM devices with standard surface electrodes fabricated on an identical material. The recessed electrode structure also resulted in lower saturation of output power at higher input powers, enabling it to take advantage of higher input powers. [less ▲] Detailed reference viewed: 99 (0 UL)![]() ; Marso, Michel ![]() in Proceedings of 6th Intern. Conf. Advanced Semicon. Dev. & Microsystems ASDAM’06 (2006) We have fabricated and characterized photomixers based on high energy nitrogen-ion-implanted GaAs. For material optimization and annealing dynamics in MSM photodetector structures, we used 400 keV ... [more ▼] We have fabricated and characterized photomixers based on high energy nitrogen-ion-implanted GaAs. For material optimization and annealing dynamics in MSM photodetector structures, we used 400 keV implantation energy with an ion dose of 1´1016 cm-2. For photomixer structures we used 3 MeV energy to implant N+ ions into GaAs substrates, with an ion concentration dose of 3´1012 cm-2. The N+-implanted GaAs photomixers exhibit improved output power in comparison to their counterparts, photomixers fabricated on low-temperature-grown GaAs. The highest output power was 2.6 μW at 850 GHz and about 1 μW at 1 THz. No saturation of the output power with increased bias voltage and optical input power was observed. These characteristics make N+-implanted GaAs the material of choice for efficient high power sources of terahertz radiation. [less ▲] Detailed reference viewed: 118 (1 UL)![]() ; ; Marso, Michel ![]() in Applied Physics Letters (2006), 89(7), 071103 The authors report on fabrication and measurement of traveling-wave photomixers based on high energy and low dose nitrogen-ion-implanted GaAs. They used 3 MeV energy to implant N+ ions into GaAs ... [more ▼] The authors report on fabrication and measurement of traveling-wave photomixers based on high energy and low dose nitrogen-ion-implanted GaAs. They used 3 MeV energy to implant N+ ions into GaAs substrates with an ion concentration dose of 3 1012 cm−2. The N+-implanted GaAs photomixers exhibit improvements in the output power in comparison with their counterparts, photomixers fabricated on low-temperature-grown GaAs. The maximal output power was 2.64 W at 850 GHz. No saturation of the output power with increased bias voltage and optical input power was observed. These characteristics make N+-implanted GaAs the material of choice for efficient high power sources of terahertz radiation. [less ▲] Detailed reference viewed: 64 (0 UL)![]() ; ; et al in Journal of Applied Physics (2006), 100 A pump experiment of two astronomical heterodyne receivers, a superconductorinsulator- superconductor SIS receiver at 450 GHz and a hot-electron-bolometer HEB receiver at 750 GHz, is reported. A low ... [more ▼] A pump experiment of two astronomical heterodyne receivers, a superconductorinsulator- superconductor SIS receiver at 450 GHz and a hot-electron-bolometer HEB receiver at 750 GHz, is reported. A low-temperature-grown GaAs metal-semiconductor-metal photonic local oscillator LO was illuminated by two near infrared semiconductor lasers, generating a beat frequency in the submillimeter range. I-V junction characteristics for different LO pump power levels demonstrate that the power delivered by the photomixer is sufficient to pump a SIS and a HEB mixer. SIS receiver noise temperatures were compared using a conventional solid-state LO anda photonic LO. In both cases, the best receiver noise temperature was identical Tsys=170 K . [less ▲] Detailed reference viewed: 114 (0 UL)![]() ; Marso, Michel ![]() in Applied Physics Letters (2005), 87(4), 41106-1-3 We report on fabrication and measurement of photomixers based on nitrogen-ion-implanted GaAs. We used energies of 500 keV, 700 keV, and 880 keV to implant N+ ions into GaAs substrates with an ion ... [more ▼] We report on fabrication and measurement of photomixers based on nitrogen-ion-implanted GaAs. We used energies of 500 keV, 700 keV, and 880 keV to implant N+ ions into GaAs substrates with an ion concentration of 3 1012 cm−2. The resulting material exhibited 110 fs carrier lifetime due to implantation-induced defects. Our photomixers were fabricated as metal-semiconductor-metal devices, placed at the feed point of a broadband antenna. Optoelectronic measurements were performed in the wavelength range between 350 nm and 950 nm. In comparison to their counterparts photomixers fabricated on low-temperature-grown GaAs the N+-implanted GaAs photomixers exhibit improvements on both the output power and responsivity. A maximal responsivity of above 100 mA/W was achieved and we did not observe any dependence of the mixer cut-off frequency on the bias voltage. These characteristics make N+-implanted GaAs the material of choice for efficient optoelectronic photomixers. [less ▲] Detailed reference viewed: 97 (0 UL)![]() ; ; et al in Applied Physics Letters (2005), 86(11), 111120-111123 A large-aperture design for terahertz traveling-wave photomixers, continuously pumped free space by two detuned diode lasers, is proposed and experimentally verified for devices based on low-temperature ... [more ▼] A large-aperture design for terahertz traveling-wave photomixers, continuously pumped free space by two detuned diode lasers, is proposed and experimentally verified for devices based on low-temperature-grown GaAs sLT-GaAsd. It combines the advantages of conventional interdigitated small-area structures and traveling-wave devices. An output power of 1 µW at the mixing frequency of 1 THz was measured in initial testing, which meets local oscillator power requirements for superconducting heterodyne mixer devices. [less ▲] Detailed reference viewed: 90 (0 UL)![]() ; ; Marso, Michel ![]() in SPIE (2004), 5498 (2004) Detailed reference viewed: 84 (1 UL) |
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