Millimeter-Wave Band Electro-Optical Imaging System Using Polarization CMOS Image Sensor and Amplified Optical Local Oscillator Source
Ryoma Okada,
Maya Mizuno,
Tomoaki Nagaoka,
Hironari Takehara,
Makito Haruta,
Hiroyuki Tashiro,
Jun Ohta,
Kiyotaka Sasagawa
Affiliations
Ryoma Okada
Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma 630-0192, Nara, Japan
Maya Mizuno
Radio Research Institute, National Institute of Information and Communications Technology, 4-2-1, Nukui-Kitamach, Koganei 184-8795, Tokyo, Japan
Tomoaki Nagaoka
Radio Research Institute, National Institute of Information and Communications Technology, 4-2-1, Nukui-Kitamach, Koganei 184-8795, Tokyo, Japan
Hironari Takehara
Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma 630-0192, Nara, Japan
Makito Haruta
Department of Opto-Electronic System Engineering, Chitose Institute of Science and Technology, 758-65, Bibi, Chitose 066-8655, Hokkaido, Japan
Hiroyuki Tashiro
Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma 630-0192, Nara, Japan
Jun Ohta
Institute for Research Initiatives, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma 630-0192, Nara, Japan
Kiyotaka Sasagawa
Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma 630-0192, Nara, Japan
In this study, we developed and demonstrated a millimeter-wave electric field imaging system using an electro-optic crystal and a highly sensitive polarization measurement technique using a polarization image sensor, which was fabricated using a 0.35-µm standard CMOS process. The polarization image sensor was equipped with differential amplifiers that amplified the difference between the 0° and 90° pixels. With the amplifier, the signal-to-noise ratio at low incident light levels was improved. Also, an optical modulator and a semiconductor optical amplifier were used to generate an optical local oscillator (LO) signal with a high modulation accuracy and sufficient optical intensity. By combining the amplified LO signal and a highly sensitive polarization imaging system, we successfully performed millimeter-wave electric field imaging with a spatial resolution of 30×60 µm at a rate of 1 FPS, corresponding to 2400 pixels/s.
