Anritsu Corporation

Koji Kawakita

Isao Kobayashi

Hiroshi Furukawa

Takao Tanimoto

Shigeru Kinugawa

The present invention provides an optical phase modulation evaluating device that can measure and evaluate the precise degree of modulation in phase of an optical phase modulation signal in comparison with the conventionally-known optical phase modulation evaluating device. The optical phase modulation evaluating module includes: a bit delay device located on optical paths of the third and fifth light beams, and adapted to change the length of the optical paths to delay the third and fifth light beams by one bit per second; and an optical phase difference setting means for delaying either or both the ninth and tenth light beams by a designated phase angle which is not equal to zero, the optical phase difference setting means having a light transmissive plate located on an optical path for the ninth light beam, and a light transmissive plate located on an optical path for the tenth light beam.

Optical phase-modulation evaluating device

A multi-wavelength light source apparatus includes a tunable light source, optical intensity modulator, optical coupler, annular optical delay circuit, and optical gate device. The tunable light source successively changes and outputs a plurality of output lights different in wavelength from one another. The optical intensity modulator outputs a modulated signal light obtained by modulating an amplitude of the output light outputted from the tunable light source over a predetermined time. The optical coupler is optically connected to the optical intensity modulator, and receives the light outputted from the optical intensity modulator. The annular optical delay circuit is optically connected to the optical coupler, and delays a part of the output light outputted from the optical intensity modulator over a time longer than the predetermined time. The optical gate device is optically connected to the optical coupler, receives the output light outputted from the optical intensity modulator and the light passed via the annular optical delay circuit to open a gate at a timing and time width such that all of the signal light modulated over the predetermined time is included one by one for each of the plurality of wavelengths.

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Atsugi, Japan

Koji Kawakita