Solid-State Circuits IEEE International Conference, 2004
This paper describes an IC technology for high-speed wireless-link systems, using photonic techni... more This paper describes an IC technology for high-speed wireless-link systems, using photonic techniques, which provides 10 Gb/s at 120 GHz. Optical signals are converted to electrical signals and radiated into freespace using Si-based circuitry. Both the preamp and PA utilize 0.1 μm gate InAlAs/InGaAs HEMTs with gains of 6-10 dB and 8.5 dB, respectively.
2011 International Topical Meeting on Microwave Photonics jointly held with the 2011 Asia-Pacific Microwave Photonics Conference, 2011
ABSTRACT We demonstrate homodyne detection of microwaves using low-temperature-grown (LTG) GaAs w... more ABSTRACT We demonstrate homodyne detection of microwaves using low-temperature-grown (LTG) GaAs with 1.55-µm optical local oscillator (LO). The sensitivity of the detection is almost proportional to the average power of the optical LO, which indicates that the photoresponse of the LTG-GaAs is linear process in our case. The dynamic range of the detection is more than 50 dB. About −22 dBm of 14.6 GHz emitted from a patch antenna is detected. The possibility for terahertz wave homodyne detection has been discussed.
ABSTRACT This paper presents a terahertz (THz) tomographic imaging system using monochromatic 400... more ABSTRACT This paper presents a terahertz (THz) tomographic imaging system using monochromatic 400~800-GHz signals, which have been generated and swept by photonic techniques. Measurable thickness of plastic plates has been experimentally verified as small as 0.37 mm, which corresponds to a depth resolution of 0.61 mm in the air.
IEEE Journal of Selected Topics in Quantum Electronics, 1996
A pulse-rate-tunable, highly extinctive, ultra-highspeed electrooptic pulse pattern generator has... more A pulse-rate-tunable, highly extinctive, ultra-highspeed electrooptic pulse pattern generator has been developed. The optical short pulse generation is based on sinusoidal electrooptic phase modulation and linear chirp compensation using a dispersive medium. Filtering the nonlinear chirp components generated by sinusoidal phase modulation drastically improves the pulse extinction, and makes nearly background-free picosecond pulsation over a wide pulse-rate range even when
We estimate the phase velocity of a modulation microwave in a quasi-velocity-matched (QVM) electr... more We estimate the phase velocity of a modulation microwave in a quasi-velocity-matched (QVM) electro-optic (EO) phase modulator (QVM-EOM) using EO sampling which is accurate and the most reliable technique for measuring voltage waveforms at an electrode. The substrate of the measured QVM-EOM is a stoichiometric periodically domain-invertedLiTaO3crystal. The electric field of a standing wave in a resonant microstrip line (width: 0.5 mm, height: 0.5 mm) is measured by employing a CdTe crystal as an EO sensor. The wavelength of the traveling microwave at 16.0801 GHz is determined as 3.33 mm by fitting the theoretical curve to the measured electric field distribution. The phase velocity is estimated asvm=5.35×107 m/s, though there exists about 5% systematic error due to the perturbation by the EO sensor. Relative dielectric constant ofεr=41.5is led as the maximum likelihood value that derives the estimated phase velocity.
Solid-State Circuits IEEE International Conference, 2004
This paper describes an IC technology for high-speed wireless-link systems, using photonic techni... more This paper describes an IC technology for high-speed wireless-link systems, using photonic techniques, which provides 10 Gb/s at 120 GHz. Optical signals are converted to electrical signals and radiated into freespace using Si-based circuitry. Both the preamp and PA utilize 0.1 μm gate InAlAs/InGaAs HEMTs with gains of 6-10 dB and 8.5 dB, respectively.
2011 International Topical Meeting on Microwave Photonics jointly held with the 2011 Asia-Pacific Microwave Photonics Conference, 2011
ABSTRACT We demonstrate homodyne detection of microwaves using low-temperature-grown (LTG) GaAs w... more ABSTRACT We demonstrate homodyne detection of microwaves using low-temperature-grown (LTG) GaAs with 1.55-µm optical local oscillator (LO). The sensitivity of the detection is almost proportional to the average power of the optical LO, which indicates that the photoresponse of the LTG-GaAs is linear process in our case. The dynamic range of the detection is more than 50 dB. About −22 dBm of 14.6 GHz emitted from a patch antenna is detected. The possibility for terahertz wave homodyne detection has been discussed.
ABSTRACT This paper presents a terahertz (THz) tomographic imaging system using monochromatic 400... more ABSTRACT This paper presents a terahertz (THz) tomographic imaging system using monochromatic 400~800-GHz signals, which have been generated and swept by photonic techniques. Measurable thickness of plastic plates has been experimentally verified as small as 0.37 mm, which corresponds to a depth resolution of 0.61 mm in the air.
IEEE Journal of Selected Topics in Quantum Electronics, 1996
A pulse-rate-tunable, highly extinctive, ultra-highspeed electrooptic pulse pattern generator has... more A pulse-rate-tunable, highly extinctive, ultra-highspeed electrooptic pulse pattern generator has been developed. The optical short pulse generation is based on sinusoidal electrooptic phase modulation and linear chirp compensation using a dispersive medium. Filtering the nonlinear chirp components generated by sinusoidal phase modulation drastically improves the pulse extinction, and makes nearly background-free picosecond pulsation over a wide pulse-rate range even when
We estimate the phase velocity of a modulation microwave in a quasi-velocity-matched (QVM) electr... more We estimate the phase velocity of a modulation microwave in a quasi-velocity-matched (QVM) electro-optic (EO) phase modulator (QVM-EOM) using EO sampling which is accurate and the most reliable technique for measuring voltage waveforms at an electrode. The substrate of the measured QVM-EOM is a stoichiometric periodically domain-invertedLiTaO3crystal. The electric field of a standing wave in a resonant microstrip line (width: 0.5 mm, height: 0.5 mm) is measured by employing a CdTe crystal as an EO sensor. The wavelength of the traveling microwave at 16.0801 GHz is determined as 3.33 mm by fitting the theoretical curve to the measured electric field distribution. The phase velocity is estimated asvm=5.35×107 m/s, though there exists about 5% systematic error due to the perturbation by the EO sensor. Relative dielectric constant ofεr=41.5is led as the maximum likelihood value that derives the estimated phase velocity.
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Papers by T. Nagatsuma