A medical instrument is described that includes an optical source, an optical fiber, and a waveguide patterned upon a substrate. The optical fiber receives radiation from the optical source and includes a first segment and a second segment. The second segment is rotated about an optical axis relative to the first segment. The waveguide receives radiation from the optical source and guides a beam of radiation. The waveguide includes a first waveguide segment designed to impart a first differential group delay on the beam of radiation and a second waveguide segment designed to impart a second differential group delay on the beam of radiation. A sum of the first differential group delay and the second differential group delay is substantially zero.

In order to provide a configuration for suppressing deterioration in the transmission quality of a signal light due to a nonlinear phenomenon in an optical fiber, a polarization dispersion adder is provided with: a polarization rotation unit which, with respect to each pulse of signal light generated by modulating a light carrier, rotates and outputs the polarization of the pulse during a period from a pulse rise start time (T0) to a pulse fall completion time (T1); and a delay addition unit which adds a delay of an amount corresponding to the rotation amount of the polarization added by the polarization rotation unit to the pulse outputted from the polarization rotation unit.

A medical instrument is described that includes an optical source, an optical fiber, and a waveguide patterned upon a substrate. The optical fiber receives radiation from the optical source and includes a first segment and a second segment. The second segment is rotated about an optical axis relative to the first segment. The waveguide receives radiation from the optical source and guides a beam of radiation. The waveguide includes a first waveguide segment designed to impart a first differential group delay on the beam of radiation and a second waveguide segment designed to impart a second differential group delay on the beam of radiation. A sum of the first differential group delay and the second differential group delay is substantially zero.

A medical instrument is described that includes an optical source, an optical fiber, and a waveguide patterned upon a substrate. The optical fiber receives radiation from the optical source and includes a first segment and a second segment. The second segment is rotated about an optical axis relative to the first segment. The waveguide receives radiation from the optical source and guides a beam of radiation. The waveguide includes a first waveguide segment designed to impart a first differential group delay on the beam of radiation and a second waveguide segment designed to impart a second differential group delay on the beam of radiation. A sum of the first differential group delay and the second differential group delay is substantially zero.

According to an example aspect, there is provided an apparatus comprising a first optical converter coupled to a fiber interface and to two waveguides, a dual rail encoder configured to encode dual rail form light from the two waveguides with payload information, and wherein the dual rail encoder is coupled to the first optical converter or to a second optical converter disposed between the dual rail encoder and the fiber interface, and wherein the first optical converter or the second optical converter is coupled so as to provide polarization encoded light into the fiber interface.

Aspects of the present disclosure describe fiber nonlinearity induced transmission penalties are reduced both in fibers with large polarization-mode dispersion, and in coupled-core multicore fibers (CC-MCF). In the case of coupled multi-core fibers, the requirement for modal delay is less.

In order to provide a configuration for suppressing deterioration in the transmission quality of a signal light due to a nonlinear phenomenon in an optical fiber, a polarization dispersion adder is provided with: a polarization rotation unit which, with respect to each pulse of signal light generated by modulating a light carrier, rotates and outputs the polarization of the pulse during a period from a pulse rise start time (T0) to a pulse fall completion time (T1); and a delay addition unit which adds a delay of an amount corresponding to the rotation amount of the polarization added by the polarization rotation unit to the pulse outputted from the polarization rotation unit.

A medical instrument is described that includes an optical source, an optical fiber, and a waveguide patterned upon a substrate. The optical fiber receives radiation from the optical source and includes a first segment and a second segment. The second segment is rotated about an optical axis relative to the first segment. The waveguide receives radiation from the optical source and guides a beam of radiation. The waveguide includes a first waveguide segment designed to impart a first differential group delay on the beam of radiation and a second waveguide segment designed to impart a second differential group delay on the beam of radiation. A sum of the first differential group delay and the second differential group delay is substantially zero.

Aspects of the present disclosure describe fiber nonlinearity induced transmission penalties are reduced both in fibers with large polarization-mode dispersion, and in coupled-core multicore fibers (CC-MCF). In the case of coupled multi-core fibers, the requirement for modal delay is less.

According to an example aspect, there is provided an apparatus comprising a first optical converter coupled to a fibre interface and to two waveguides, a dual rail encoder configured to encode dual rail form light from the two waveguides with payload information, and wherein the dual rail encoder is coupled to the first optical converter or to a second optical converter disposed between the dual rail encoder and the fibre interface, and wherein the first optical converter or the second optical converter is coupled so as to provide polarization encoded light into the fibre interface.