Abstract: An isolator 10 includes a substrate 11, waveguide portions 12, an insulating layer 13, and a non-reciprocal member 14. The waveguide portions 12 extend along a main surface of the substrate 11, and are positioned side by side on the main surface. The insulating layer 13 covers at least part of outer edges of the waveguide portions 12, and includes a recess 18 overlapping with a first waveguide portion 16 when viewed in a normal direction of the main surface. The non-reciprocal member 14 overlaps with at least part of the first waveguide portion 16 inside the recess 18 when viewed in the normal direction. In a cross-section perpendicular to an extension direction of the first waveguide portion 16, expressions (1) and (2) are satisfied: w1?w3?mfd1+mfd2?w2?2×x . . . (1), x?(mfd2?w2)/2 . . . (2).

Abstract: An optical integrated circuit includes a substrate including a substrate surface, a first waveguide and a second waveguide configured to allow electromagnetic waves to propagate along the substrate surface, and a non-reciprocal member disposed on a side of the first waveguide and the second waveguide remote from the substrate surface. At least part of the non-reciprocal member is disposed in a range of a mode field diameter of TM mode electromagnetic waves in the first waveguide. The non-reciprocal member is not disposed in a range of a mode field diameter of TM mode electromagnetic waves in the second waveguide.

Abstract: An optical integrated circuit includes: a waveguide including a first part and a second part and configured to couple an electromagnetic wave propagating in the first part and an electromagnetic wave propagating in the second part; and a non-reciprocal member positioned alongside the second part in an amplitude direction of an electric field component of the electromagnetic wave. In a range where the first part and the second part are coupled with each other, deviation between a center of an energy distribution of an electric field component of the electromagnetic wave propagating in the first part and a center of an energy distribution of an electric field component of the electromagnetic wave propagating in the second part falls within a prescribed range.

Abstract: An isolator includes a substrate, a waveguide, an insulating layer, and a non-reciprocity member. The insulating layer includes a recess. The recess overlaps at least part of the waveguide. The non-reciprocity member is positioned in the recess. The waveguide includes a first waveguide and a second waveguide. The recess includes a first recess and a second recess. The non-reciprocity member includes a first non-reciprocity member positioned in the first recess and a second non-reciprocity member positioned in the second recess. A propagation direction of the electromagnetic wave in a portion of the first waveguide, the portion overlapping the first non-reciprocity member, and a propagation direction of the electromagnetic wave in a portion of the second waveguide, the portion overlapping the second non-reciprocity member, are different from each other.

Abstract: An isolator 10 includes a substrate 11, waveguide portions 12, an insulating layer 13, and a non-reciprocal member 14. The waveguide portions 12 extend along a main surface of the substrate 11, and are positioned side by side on the main surface. The insulating layer 13 covers at least part of outer edges of the waveguide portions 12, and includes a recess 18 overlapping with a first waveguide portion 16 when viewed in a normal direction of the main surface. The non-reciprocal member 14 overlaps with at least part of the first waveguide portion 16 inside the recess 18 when viewed in the normal direction. In a cross-section perpendicular to an extension direction of the first waveguide portion 16, expressions (1) and (2) are satisfied: w1?w3?mfd1+mfd2?w2?2xx . . . (1), x?(mfd2?w2)/2 . . . (2).

Abstract: An optical integrated circuit includes a substrate including a substrate surface, a first waveguide and a second waveguide configured to allow electromagnetic waves to propagate along the substrate surface, and a non-reciprocal member disposed on a side of the first waveguide and the second waveguide remote from the substrate surface. At least part of the non-reciprocal member is disposed in a range of a mode field diameter of TM mode electromagnetic waves in the first waveguide. The non-reciprocal member is not disposed in a range of a mode field diameter of TM mode electromagnetic waves in the second waveguide.

Abstract: An optical integrated circuit includes: a waveguide including a first part and a second part and configured to couple an electromagnetic wave propagating in the first part and an electromagnetic wave propagating in the second part; and a non-reciprocal member positioned alongside the second part in an amplitude direction of an electric field component of the electromagnetic wave. In a range where the first part and the second part are coupled with each other, deviation between a center of an energy distribution of an electric field component of the electromagnetic wave propagating in the first part and a center of an energy distribution of an electric field component of the electromagnetic wave propagating in the second part falls within a prescribed range.

Abstract: An isolator includes a substrate, a waveguide, an insulating layer, and a non-reciprocity member. The insulating layer includes a recess. The recess overlaps at least part of the waveguide. The non-reciprocity member is positioned in the recess. The waveguide includes a first waveguide and a second waveguide. The recess includes a first recess and a second recess. The non-reciprocity member includes a first non-reciprocity member positioned in the first recess and a second non-reciprocity member positioned in the second recess. A propagation direction of the electromagnetic wave in a portion of the first waveguide, the portion overlapping the first non-reciprocity member, and a propagation direction of the electromagnetic wave in a portion of the second waveguide, the portion overlapping the second non-reciprocity member, are different from each other.