Optical circuit and method of fabricating the same

A digital type optical switch comprising:

• (a) an input optical wave guide including an electro-optic crystal;
• (b) at least two output optical wave guides connected to said input optical wave guide in Y-shaped fashion;
• (c) a signal electrode overlapping both of said two output optical wave guides, said signal electrode applying a voltage for varying an index of refraction of said output optical wave guides to thereby select one of said output optical wave guides through which an optical output is obtained, and
• wherein said output optical wave guides have domain orientations inverted with respect to each other.

An optical circuit, comprising:

• a first wave guide and a second wave guide, said first wave guide having a domain orientation different from said second optical wave guide;
• first and second Y-shaped optical fiber portions, said first Y-shaped optical fiber portion connecting first ends of said first and second optical wave guides and said second Y-shaped optical fiber portion connecting second ends of said first and second optical wave guides;
• and
• a signal electrode located at a non-overlapping center position between said first wave guide and said second wave guide, said signal electrode being the only signal electrode in said circuit.

A light modulator, including:

• two optical wave guides each including an electro-optic crystal, said two optical wave guides cooperating with each other to constitute a phase shifter and having domain orientations inverted with respect to each other;
• first and second Y-shaped optical fiber portions, said first Y-shaped optical fiber portion connecting first ends of said two optical waveguides and said second Y-shaped optical fiber portion connecting second ends of said two optical waveguides;
• and
• a first signal electrode overlapping said two optical wave guides.