There is provided an optical switch. The optical switch comprises a first optical waveguide (10), a second optical waveguide (20), a first optical ring resonator (40) and a second optical ring resonator (50). The first optical ring resonator (40) is arranged between the first optical waveguide (10) and the second optical waveguide (20), wherein the first optical ring resonator (40) is capable of coupling an optical signal travelling along the first optical waveguide (10) in a first direction to the second optical waveguide (20) such that the optical signal travels in a second direction along the second optical waveguide (20). The second optical ring resonator (50) is arranged between the first optical waveguide (10) and the second optical waveguide (20); wherein the second optical ring resonator (50) is capable of coupling an optical signal travelling along the first optical waveguide (10) in the first direction to the second optical waveguide (20) such that the optical signal travels in a third direction along the second optical waveguide (20) opposite to the second direction. There is also provided an optical network node and an optical network.