This optical modulator includes an optical modulation element having a first optical waveguide, a second optical waveguide, a first electrode configured to apply an electric field to the first optical waveguide, and a second electrode configured to apply an electric field to the second optical waveguide; and a control unit configured to control an applied voltage between the first electrode and the second electrode. The control unit sets Vpp to 0.06×Vπ≤Vpp≤0.4×Vπ when a half-wavelength voltage of the optical modulation element is Vπ and an applied voltage width that is an amplitude of an applied voltage applied to the optical modulation element is Vpp, and sets Vn≤Vmin≤Vn+0.29×Vπ or Vn−0.29×Vπ≤Vmax≤Vn when a minimum value and a maximum value of a voltage applied to the optical modulation element are respectively Vmin and Vmax and a null point voltage of the optical modulation element is Vn.

Provided is an optical phase shifter. The optical phase shifter includes: a slab waveguide in which a first slab region doped into a first conductivity type and a second slab region doped into a second conductivity type are arranged side by side to form a PN junction; and a rib waveguide disposed on the slab waveguide such that one side of the rib waveguide makes contact with the first slab region, and an opposite side of the rib waveguide makes contact with the second slab region, wherein the rib waveguide includes first to third rib waveguide layers that are sequentially stacked, the first and third rib waveguide layers include silicon (Si), and the second rib waveguide layer includes silicon-germanium (SiGe).

The invention refers to an optical device for heterodyne interferometry, comprising a chip, a beam splitter, a first waveguide arranged on the chip, light propagating in the first waveguide being guided to the beam splitter, a second waveguide arranged on the chip, light propagating in the second waveguide being guided to and/or from the beam splitter, wherein the beam splitter, the first waveguide, and the second waveguide form part of a Michelson interferometer, wherein the first waveguide and the second waveguide at least partially form two arms of the Michelson interferometer, and wherein two further arms of the Michelson interferometer are at least partially arranged outside the chip.

Provided are a single-photon source device and a single-photon source system including same. The single-photon source device includes a substrate, a straight waveguide extending in a first direction on the substrate, a first coupling layer which is provided on the straight waveguide and has a first point defect, at least one first electrode which is adjacent to the first point defect and provided on the first coupling layer, a ring waveguide which is adjacent to the straight waveguide and provided on the substrate, and at least one second electrode provided on the ring waveguide.

The present disclosure describes an optical waveguide provided with an incident side reflection film and an emission side reflection film to resonate light incident via the incident side reflection film and formed to penetrate from the incident side reflection film to the emission side reflection film for propagating resonated light. The disclosure also includes a substrate to which the optical waveguide is formed from a top surface thereof and a first protection member and a second protection member formed with a material corresponding to a material of the substrate, wherein the first protection member and the second protection member are arranged on the optical waveguide such that one end facet of the first protection member forms an identical plane with a first end facet of the substrate including an optical incident end.

An optical waveguide (100) is disclosed, for guiding light in a photonic circuit comprising a layer of phase change material (101) for modulating the phase of the guided light. The phase change material (101) is switchable between at least a stable crystalline state and a stable amorphous state each with different refractive indexes. The phase change material (101) exhibits an extinction coefficient of less than 0.1 in both states for wavelengths greater than 1000 nm.

A generator device for generating an arbitrary optical pulse pattern includes: a light source to provide primary laser pulses, a distributor to provide a plurality of primary optical pulses by distributing light of the primary laser pulses (LB00.sub.k) into a plurality of branches, a combiner to form an output signal by combining modulated optical signals from the branches, and a controller unit to provide control signals for controlling optical modulators of the branches, wherein a first branch comprises a first optical modulator to form a first modulated optical signal from primary optical pulses of the first branch, wherein a second branch comprises a second optical modulator to form a second modulated optical signal from primary optical pulses of the second branch, and wherein a propagation delay of the second branch is different from a propagation delay of the first branch.

Embodiments are disclosed for generating an optical Pulse Amplitude Modulation 4-level (PAM-4) signal from bandwidth-limited duobinary electrical signals in a Mach-Zehnder modulator. An example system includes an MZM structure that comprises a first waveguide interferometer arm structure associated with a first semiconductor device and a second waveguide interferometer arm structure associated with a second semiconductor device. A polybinary electrical signal is applied to or between the first semiconductor device and the second semiconductor device to convert an input optical signal provided to the MZM structure into an optical PAM-4 signal.

An optical phase modulator (2) includes a first 2×2 Mach-Zehnder optical phase modulation unit (10). The first 2×2 Mach-Zehnder optical phase modulation unit (10) includes a first 2×2 multimode interference waveguide (11), a second 2×2 multimode interference waveguide (14), a pair of first arm waveguides (12, 13), and first modulation electrodes (15, 16). A first output port (an output port 17d) of the first 2×2 Mach-Zehnder optical phase modulation unit (10 ) is a cross port to a first input port (an input port 17a) of the first 2×2 Mach-Zehnder optical phase modulation unit (10).

An optical phase modulator (2) includes a first 2×2 Mach-Zehnder optical phase modulation unit (10). The first 2×2 Mach-Zehnder optical phase modulation unit (10) includes a first 2×2 multimode interference waveguide (11), a second 2×2 multimode interference waveguide (14), a pair of first arm waveguides (12, 13), and first modulation electrodes (15, 16). A first output port (an output port 17d) of the first 2×2 Mach-Zehnder optical phase modulation unit (10 ) is a cross port to a first input port (an input port 17a) of the first 2×2 Mach-Zehnder optical phase modulation unit (10).