An optical device that includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a substrate; and a waveguide is provided, wherein the waveguide and the magnetic element are located on or above the substrate, and wherein at least some of light propagating in the waveguide is applied to the magnetic element.

An optical phase shifter according to an embodiment for achieving the object of the present disclosure includes a first semiconductor layer formed on a substrate, a second semiconductor layer having opposite polarity to the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and including ferroelectrics, a first electrode connected to the first semiconductor layer, and a second electrode connected to the second semiconductor layer. According to an embodiment, the introduction of ferroelectric materials to a semiconductor-insulator-semiconductor (SIS) optical phase shifter brings about improvement in charge collection efficiency resulting from the negative capacitance effect, thereby achieving higher phase modulation efficiency and lower power consumption. Additionally, it is possible to realize a new structure of optical switch or modulator device through design changes of the type of ferroelectrics and the structural variables.

An optical phase shifter according to an embodiment for achieving the object of the present disclosure includes a first semiconductor layer formed on a substrate, a second semiconductor layer having opposite polarity to the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and including ferroelectrics, a first electrode connected to the first semiconductor layer, and a second electrode connected to the second semiconductor layer. According to an embodiment, the introduction of ferroelectric materials to a semiconductor-insulator-semiconductor (SIS) optical phase shifter brings about improvement in charge collection efficiency resulting from the negative capacitance effect, thereby achieving higher phase modulation efficiency and lower power consumption. Additionally, it is possible to realize a new structure of optical switch or modulator device through design changes of the type of ferroelectrics and the structural variables.

An optical device that includes at least one magnetic element including a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer sandwiched between the first ferromagnetic layer and the second ferromagnetic layer; a substrate; and a waveguide is provided, wherein the waveguide and the magnetic element are located on or above the substrate, and wherein at least some of light propagating in the waveguide is applied to the magnetic element.