National Institute of Information and Communications Technology, Incorporated

Sumitomo Osaka Cement Co., Ltd.

Akito Chiba

Tetsuya Kawanishi

Masahiro Tsuchiya

Junichiro Ichikawa

Takahide Sakamoto

Masaaki Sudo

A method for evaluating a characteristic of, especially, each of Mach-Zehnder interferometers (MZIs) of an optical modulator. The method includes a step of measuring the intensity of the output of the optical modulator containing MZIs and a step of evaluating a characteristic of each MZI by using the sideband. The output intensity measuring step is the one of measuring the intensity Sof the sideband signal contained in the output light from the optical modulator. The characteristic evaluating step is the one of evaluating a characteristic of the MZIby using the S.

Method for evaluating characteristic of optical modulator having mach-zehnder interferometer

A quadrature amplitude modulation (QAM) signal generator, which can obtain optical signals such as QAM signals without handling multilevel electrical signals, can be produced by using a plurality of parallel Mach-Zehnder modulators (MZMs), such as quadruplex parallel MZMs (QPMZM). The quadrature amplitude modulation (QAM) signal generator includes a first waveguide, a first quadrature phase-shift-keying (QPSK) signal generator provided on the first waveguide, a second waveguide connected with the first waveguide at a wave-combining point, and a second quadrature phase-shift-keying (QPSK) signal generator provided on the second waveguide.

Quadrature amplitude modulation signal generating device

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Tokyo, Japan

Akito Chiba