Nippon Telegraph and Telephone Corporation

Touru Matsuura

Takashi Kurihara

Tadayuki Imai

Kazuo Fujiura

Seiji Toyoda

Masahiro Sasaura

Koji Enbutsu

Akiyuki Tate

Makoto Shimokozono

Hiroshi Fushimi

The present invention provides an optical switch, an optical modulator, and a wavelength variable filter each of which has a simple configuration, which requires only a low driving voltage, which is independent of polarization, and which can operate at high speed. An optical switch according to the present invention includes a 3-dB coupler () placed on an input, a 3-dB coupler () placed on an output, and two optical waveguides connecting the input-side 3-dB coupler and the output-side 3-dB coupler together. The optical switch also includes a phase modulating section () that applies electric fields to one or both of the two optical waveguides. At least two optical waveguides are a crystal material including KTaNbO(0&#x3c;x&#x3c;1) and KLiTaNbO(0&#x3c;x&#x3c;1, 0&#x3c;y&#x3c;1), or KTaNbOor KLiTaNbO.

Optical switch, optical modulator and wavelength variable filter

An optical switch, an optical modulator, and a wavelength variable filter each have a simple configuration, which requires only a low driving voltage, which is independent of polarization, and which can operate at high speed. An optical switch includes a 3-dB coupler placed on an output, a 3-dB coupler placed on an output, and two optical waveguides connecting the input-side 3-dB coupler and the output-side 3-dB coupler together. The optical switch also includes a phase modulating section that applies electric fields to one or both of the two optical waveguides. At least two optical waveguides are a crystal material including KTaNbO(0&#x3c;x&#x3c;1) and KLiTaNbO(0&#x3c;x&#x3c;1, 0&#x3c;y&#x3c;1), or KTaNbOor KLiTaNbO.

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Yokohama, Japan

Touru Matsuura