A connector that connects a first multi-core optical fiber to which a first plug is provided and a second multi-core optical fiber to which a second plug is provided to one another, includes: a first jack for inserting the first plug; and a second jack for inserting the second plug, wherein the first jack is configured so that the first plug in a first state and the first plug in a second state can at least be inserted thereinto, and the first plug in the second state is obtained by rotating the first plug in the first state by 180 degrees about an insertion direction as the axis of rotation, the insertion direction being the direction in which the first plug is inserted into the first jack.

The present disclosure provides a multi-core fiber (MCF) and manufacturing method thereof and an MCF marker (or marker). The MCF (100) comprises a plurality of cores (102) and a marker (108). Each core is associated with a core diameter (104) and a core-placement-radius (106) and the marker (108) is associated with a marker diameter (110) and a marker-placement-radius (112). The marker has a marker core (116) and a marker clad (118) with a D/d ratio between 5 to 20. During manufacturing, the MCF is drawn from a preform assembly (200) having a top hollow handle (202) with a handle thickness (114) attached on a top end of a glass preform (204) that has a plurality of core holes (206) and a marker hole (210), wherein the marker hole (210) is at least partially covered by the top hollow handle of the handle thickness (114).

Disclosed is a multi-core optical fiber including a plurality of cores extending parallelly along a central axis of the multi-core optical fiber, and defining a plurality of spatial paths such that each core of the plurality of cores has a refractive index profile having a predefined core alpha value in a range from about 5 to about 9. A core pitch between each pair of cores of the plurality of cores is in a range from about 35 micrometres to about 45 micrometres. Further, at least one core of the plurality of cores has (i) a refractive index profile different from other cores of the plurality of cores, and (ii) a core diameter different from the other cores of the plurality of cores.

Disclosed is a multi-core optical fiber having a plurality of cores extending parallelly along a central axis of the multi-core optical fiber. Each core of the plurality of cores is up-doped with an up-dopant. The multi-core optical fiber further has a plurality of buffer layers such that each buffer layer of the plurality of buffer layers envelop a corresponding core of the plurality of cores. Each buffer layer of the plurality of buffer layers has a predefined buffer layer thickness. The multi-core optical fiber further has a plurality of trench layers such that each trench layer of the plurality of trench layers envelops a corresponding buffer layer of the plurality of buffer layers. Each trench layer of the plurality of trench layers is down-doped with a down-dopant. The multi-core optical fiber has an inter-core crosstalk of less than −30 decibel/kilometres (dB/km) at a wavelength of 1550 nanometres (nm).

The invention relates to multicore fiber imaging, such as used in endoscopy. Methods are described for processing images captured with such systems to achieve an improved depth of field image or extract 3D information concerning the images, without requiring the addition of additional optical components. One method for generating an image from light received by an imager via a multiplicity of waveguides includes receiving a digital image containing a plurality of pixels, the digital image including a plurality of regions within it wherein each of said regions corresponds to a waveguide core. Each region includes a plurality of pixels, and a first subset of pixels within each region is defined which at least partly correlates with light having been received at a corresponding core in a first spatial arrangement, the subset including less than all of the pixels within a region. A first image is generated from the first subset of pixels from said regions, combined to form an image over the whole waveguide array. The first spatial arrangement may correspond to a measure of angular dimension of the incident light for that region. In addition to increased depth of field, the modified images provided by the invention allow 3D visualisation of objects, eg. using stereographs or depth mapping techniques.

A method and equipment for dimensional measurement of a micro part based on fiber laser with multi-core fiber Bragg grating probe are provided, wherein a multi-core FBG probe with FBGs (12,29) inscribed in the core or cores out of the center of the multi-core fiber is used to transform the two-dimensional or three-dimensional contact displacement into the spectrum shifts with a high sensitivity. At the meantime, the FBGs in the multi-core FBG probe (12,29) work as the wavelength selection device of the fiber laser, the wavelength of the fiber laser will change thereby. So the contact displacement is finally converted into the wavelength change of the fiber laser. The method and equipment have the advantage of high sensitivity, low probing force, compact structure, high inspecting aspect ratio and immunity to environment interference.

The present embodiment relates to a method of directly measuring a leakage loss from a peripheral core in a MCF with a coating to the coating. In the measurement method, in a high refractive-index state in which the coating is present on an outer periphery of a common cladding, first transmission power of measurement light, which propagates through the peripheral core of the MCF, is measured. On the other hand, in a low refractive-index state in which a low-refractive-index layer with a lower refractive index than the common cladding is provided on the outer periphery of the common cladding, second transmission power of the measurement light, which propagates through the peripheral core of the MCF, is measured. The leakage loss LL from the peripheral core to the coating is calculated as a difference between the first transmission power and the second transmission power.

A multicore fiber is provided that includes a plurality of elliptical cores spaced apart from one another. Each of the plurality of elliptical cores has an elliptical shape. The multicore fiber also includes a cladding surrounding the plurality of elliptical cores.

Disclosed is an optical waveguide, for transmitting a guided optical light beam having a wavelength greater than 180 nm. The waveguide includes a core layer for guiding light made of a first material having a first index of refraction, and a cladding layer made of a thermoplastic elastomer. Also disclosed are: a medical device and also to a waveguide sensor including the optical waveguide of the invention; a method of fabrication of the optical waveguide. The method includes a step of providing a thermoplastic elastomer preform having a central longitudinal aperture for introducing a liquid polymer, before or after reducing and elongating the preform to a predetermined length and lateral dimension. The method includes a polymerizing step of the core of the formed optical waveguide; and use of the optical waveguide in association with a surgical instrument.

A photon detection device, configured to couple to a multicore optical fibre, the device comprising a plurality of detection regions, each detection region being arranged to align with just a single core of the multicore optical fibre when the device is coupled to the multicore optical fibre.