An integrated photonic device (100; 200; 300; 400; 500) comprising: an input waveguide arrangement comprising an input waveguide configured to extend in an input plane, and an output waveguide arrangement comprising an output waveguide configured to extend in an output plane, wherein the output plane is parallel to or contained within the input plane; an input coupler (106; 206; 316; 320; 422; 526) optically coupled to the input waveguide , wherein the input coupler (106; 206; 316; 320; 422; 526) is configured to redirect a light signal (108; 208a, 208b; 308) out of the input waveguide and the input plane; a light property modifier (110; 210a; 210b; 310) configured to receive the light signal (108; 208a; 208b; 308) from the input coupler (106; 206; 316; 320; 422; 526) and reflect the light signal (108; 208a; 208b; 308) towards the output plane; an output coupler; wherein the light signal (108; 208a; 208b; 308) received by the light property modifier (110; 210a; 210b; 310) from the input coupler (106; 206; 316; 320; 422; 526) is redirected by the light property modifier (110; 210a; 210b; 310) to the output coupler (112; 212; 318; 424; 528), wherein the output coupler (112; 212; 318; 424; 528) is optically coupled to the output waveguide and is configured to receive the reflected light signal (108; 208a; 208b; 308) from the light property modifier (110; 210a; 210b; 310) and redirect the light signal (108; 208a; 208b; 308) into the output waveguide and the output plane, characterised in that the light property modifier (110; 21 0a; 21 0b; 310) is configured to selectively adjust an optical path length of the light signal (108; 208a; 208b;308) between the input coupler (106; 206; 316; 320; 422; 526) and the output coupler (112; 212; 318; 424; 528). an input waveguide arrangement comprising an input waveguide configured to extend in an input plane, and an output waveguide arrangement comprising an output waveguide configured to extend in an output plane, wherein the output plane is parallel to or contained within the input plane; an input coupler (106; 206; 316; 320; 422; 526) optically coupled to the input waveguide , wherein the input coupler (106; 206; 316; 320; 422; 526) is configured to redirect a light signal (108; 208a, 208b; 308) out of the input waveguide and the input plane; a light property modifier (110; 210a; 210b; 310) configured to receive the light signal (108; 208a; 208b; 308) from the input coupler (106; 206; 316; 320; 422; 526) and reflect the light signal (108; 208a; 208b; 308) towards the output plane; an output coupler; wherein the light signal (108; 208a; 208b; 308) received by the light property modifier (110; 210a; 210b; 310) from the input coupler (106; 206; 316; 320; 422; 526) is redirected by the light property modifier (110; 210a; 210b; 310) to the output coupler (112; 212; 318; 424; 528), wherein the output coupler (112; 212; 318; 424; 528) is optically coupled to the output waveguide and is configured to receive the reflected light signal (108; 208a; 208b; 308) from the light property modifier (110; 210a; 210b; 310) and redirect the light signal (108; 208a; 208b; 308) into the output waveguide and the output plane, characterised in that the light property modifier (110; 21 0a; 21 0b; 310) is configured to selectively adjust an optical path length of the light signal (108; 208a; 208b;308) between the input coupler (106; 206; 316; 320; 422; 526) and the output coupler (112; 212; 318; 424; 528). <EOS>