Abstract: A dual mode twisted string actuator using a clutch is provided. The twisted string actuator according to an exemplary embodiment of the present disclosure includes: a first actuator; a first coupler which is rotated by the first actuator; a shaft which is coupled to and interlocked with the first coupler; a second coupler which is selectively interlocked with the first coupler and comprises a plurality of string receiving portions; and a string which has one end fixed to the first coupler and the other end fixed to a moving body through the string receiving portions of the second coupler. Accordingly, it is possible to reduce the size of the existing large and heavy transmission system and to miniaturize and lighten the size of the entire drive system.

Abstract: A dual mode twisted string actuator using a clutch is provided. The twisted string actuator according to an exemplary embodiment of the present disclosure includes: a first actuator; a first coupler which is rotated by the first actuator; a shaft which is coupled to and interlocked with the first coupler; a second coupler which is selectively interlocked with the first coupler and comprises a plurality of string receiving portions; and a string which has one end fixed to the first coupler and the other end fixed to a moving body through the string receiving portions of the second coupler. Accordingly, it is possible to reduce the size of the existing large and heavy transmission system and to miniaturize and lighten the size of the entire drive system.

Abstract: An optical hybrid circuit includes an MMI coupler including input channels provided at positions symmetrical first output channels, and second output channels, to convert multilevel modulation signal into first and second optical signals each having an in-phase relationship; first optical coupler coupled to one of the first and the second output channels, and having a branching ratio of 85:15 or 15:85, to convert the first optical signals into third optical signals having a 45- or 135-degree phase relationship; second optical coupler coupled to the other of the first and the second output channels, and having a same branching ratio as that of the first optical coupler, to convert the second optical signals into fourth optical signals having a 135- or 45-degree phase relationship; and a phase controlling region provided on at least one of one of the first output channels and one of the second output channels.

Abstract: The optical waveguide device includes a first optical coupler which branches input light and outputs first signal light and second signal light, an optical phase shifter including a first and a second optical waveguides of optical path lengths different from each other and giving a phase difference between the first signal light and the second signal light, and the second optical coupler coupling the first signal light outputted from the first optical waveguide and the second signal light outputted from the second optical waveguide. The first optical waveguide and the second optical waveguide have the same waveguide width and have optical waveguides bent with substantially the same radius of curvature.

Abstract: The optical waveguide device includes a first optical coupler which branches input light and outputs first signal light and second signal light, an optical phase shifter including a first and a second optical waveguides of optical path lengths different from each other and giving a phase difference between the first signal light and the second signal light, and the second optical coupler coupling the first signal light outputted from the first optical waveguide and the second signal light outputted from the second optical waveguide. The first optical waveguide and the second optical waveguide have the same waveguide width and have optical waveguides bent with substantially the same radius of curvature.

Abstract: According to aspects of embodiments, an optical device includes a first coupler configured to split an optical signal; a second coupler configured to cause optical signals to interfere with each other, a first waveguide configured to couple the first coupler to the second coupler, the first waveguide includes a first phase shifter region having a section narrower in width than an end of the first phase shifter region, the second waveguide includes a second phase shifter region having a section wider in width than an end of the second phase shifter region.

Abstract: An optical hybrid circuit includes: a first optical coupler including a first input channel, a second input channel, a first output channel, and a second output channel; a second optical coupler including a third input channel, a fourth input channel, a third output channel, and a fourth output channel; a third optical coupler including a fifth input channel, a sixth input channel, a fifth output channel, and a sixth output channel; a fourth optical coupler including a seventh input channel, an eighth input channel, a seventh output channel, and an eighth output channel; a fifth optical coupler including a ninth input channel, a tenth input channel, a ninth output channel, and a tenth output channel, the ninth input channel coupled to the first output channel; and a sixth optical coupler including an eleventh input channel, a twelfth input channel, an eleventh output channel, and a twelfth output channel.

Abstract: An optical semiconductor device, including a first optical waveguide with a first width, a second optical waveguide with a second width narrower than the first width with a bending region, and a third optical waveguide with a third width wider than the second width and coupled to the second optical waveguide.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: An optical hybrid circuit includes a MMI coupler including a pair of input channels provided at positions symmetrical with respect to a center position in a widthwise direction thereof, a pair of first output channels outputting a pair of first optical signals having an in-phase relationship, and a pair of second output channels neighboring with each other outputting a pair of second optical signals having an in-phase relationship. The MMI coupler converts QPSK signal light or DQPSK signal light into the pair of first optical signals and the pair of second optical signals having an in-phase relationship. The optical hybrid circuit includes a 2:2 optical coupler connected to the first or the second output channels. The 2:2 optical coupler converts the pair of first optical signals or the pair of second optical signals into a pair of third optical signals having a quadrature phase relationship with the pair of first or second optical signals.

Abstract: The optical waveguide device includes a first optical coupler which branches input light and outputs first signal light and second signal light, an optical phase shifter including a first and a second optical waveguides of optical path lengths different from each other and giving a phase difference between the first signal light and the second signal light, and the second optical coupler coupling the first signal light outputted from the first optical waveguide and the second signal light outputted from the second optical waveguide. The first optical waveguide and the second optical waveguide have the same waveguide width and have optical waveguides bent with substantially the same radius of curvature.

Abstract: An optical hybrid circuit includes: a first optical coupler including a first input channel, a second input channel, a first output channel, and a second output channel; a second optical coupler including a third input channel, a fourth input channel, a third output channel, and a fourth output channel; a third optical coupler including a fifth input channel, a sixth input channel, a fifth output channel, and a sixth output channel; a fourth optical coupler including a seventh input channel, an eighth input channel, a seventh output channel, and an eighth output channel; a fifth optical coupler including a ninth input channel, a tenth input channel, a ninth output channel, and a tenth output channel, the ninth input channel coupled to the first output channel; and a sixth optical coupler including an eleventh input channel, a twelfth input channel, an eleventh output channel, and a twelfth output channel.

Abstract: An optical hybrid circuit includes an MMI coupler including input channels provided at positions symmetrical first output channels, and second output channels, to convert multilevel modulation signal into first and second optical signals each having an in-phase relationship; first optical coupler coupled to one of the first and the second output channels, and having a branching ratio of 85:15 or 15:85, to convert the first optical signals into third optical signals having a 45- or 135-degree phase relationship; second optical coupler coupled to the other of the first and the second output channels, and having a same branching ratio as that of the first optical coupler, to convert the second optical signals into fourth optical signals having a 135- or 45-degree phase relationship; and a phase controlling region provided on at least one of one of the first output channels and one of the second output channels.

Abstract: An optical waveguide element includes a first optical coupler, a second optical coupler, and a first optical waveguide and a second optical waveguide that couple an output side of the first optical coupler and an input side of the second optical coupler to each other, the first optical waveguide and the second optical waveguide each include a bent waveguide, and the first optical waveguide and the second optical waveguide are different in optical path length from each other.

Abstract: An optical waveguide device includes a plurality of input channels, a plurality of output channels, and a multi-mode interference coupler having one end part coupled to the plurality of input channels and another end part coupled to the plurality of output channels, the multi-mode interference coupler includes a first part gradually narrowing in width from the one end part to the other end part, a second part coupling to the first part and extending from the one end part to the other end part while keeping the width of a coupling part between the first part and the second part, and a third part coupling to the second part and gradually thickening in width from the one end part to the other end part.

Abstract: An optical waveguide device includes two input channels, a plurality of output channels, and a multi-mode interference coupler having one end part coupled to the two input channels and the other end part coupled to the plurality of output channels, the multi-mode interference coupler has a pair of opposite side parts, the multi-mode interference coupler has a width defined by the pair of opposite side parts and the width gradually increases from one end part to the other end part, and the two input channels are asymmetrically coupled to the one end part with respect to the center axis in the width direction.

Abstract: An optical hybrid circuit includes a multimode interference coupler; a first 2:2 optical coupler; a second 2:2 optical coupler; a third 2:2 optical coupler; and a phase controlling region. The first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled to one of the pair of first output channels, the pair of second output channels, the pair of third output channels, and the pair of fourth output channels of the multimode interference coupler. The phase controlling region is provided in one or both of each pair of at least two pairs of output channels from among three pairs of output channels to which the first 2:2 optical coupler, the second 2:2 optical coupler, and the third 2:2 optical coupler are coupled, respectively.

Abstract: According to aspects of embodiments, an optical device includes a first coupler configured to split an optical signal; a second coupler configured to cause optical signals to interfere with each other, a first waveguide configured to couple the first coupler to the second coupler, the first waveguide includes a first phase shifter region having a section narrower in width than an end of the first phase shifter region, the second waveguide includes a second phase shifter region having a section wider in width than an end of the second phase shifter region.

Abstract: An optical element includes a first and a second layer in a first and a second region respectively in light propagating direction; a first and a second core layer above the first and the second layers respectively; a top layer above the first and the second core layer, the first and the second core layer extend in succession in the light propagating direction, a first projecting section exposes a side of the first core layer is in the first region, a second projecting section exposes at least part of a side of the second core layer is in the second region, a bottom section of the first projecting section is positioned below the bottom surface of the first core layer and the second core layer, and a bottom section of the second projecting section is positioned higher than the bottom section of the first projecting section.

Abstract: An optical hybrid circuit includes a MMI coupler including a pair of input channels provided at positions symmetrical with respect to a center position in a widthwise direction thereof, a pair of first output channels outputting a pair of first optical signals having an in-phase relationship, and a pair of second output channels neighboring with each other outputting a pair of second optical signals having an in-phase relationship. The MMI coupler converts QPSK signal light or DQPSK signal light into the pair of first optical signals and the pair of second optical signals having an in-phase relationship. The optical hybrid circuit includes a 2:2 optical coupler connected to the first or the second output channels. The 2:2 optical coupler converts the pair of first optical signals or the pair of second optical signals into a pair of third optical signals having a quadrature phase relationship with the pair of first or second optical signals.