An optical component has first and second planar lightwave circuits. The first and second planar lightwave circuits are aligned and jointed such that the position of an i-th optical waveguide (where i is an integer greater than or equal to 1 and less than or equal to n) of the first planar lightwave circuit and that of an i-th optical waveguide of the second planar lightwave circuit are matched on a joint interface. An angle formed by the i-th optical waveguide of the first planar lightwave circuit and a normal of the interface is configured to vary in accordance with a value of i within a range satisfying the Snell's law.