There are provided herein test instruments, devices and methods for measuring the optical power loss of optical-fiber devices under test, and particularly those terminated with multifiber connectors, which allows for a one-cord or one-cord equivalent reference method whichever the pinning of the actual optical-fiber device under test. There is proposed to add an optical-fiber expansion device to convert the pinning of the input interface of the power meter instrument from pinned to unpinned or vice-versa, while not adding extra measurement uncertainty. This is accomplished using a patch cord which core diameter is between that of the device under test and that of the input interface of the power meter instrument.

A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

One or more embodiments are directed to optical test instruments, such as fiber optic inspection scopes and optical power meters, for testing optical communication links, such as fiber optic connectors. The optical test instruments include a single test port that is able to operate in two modes of operation. In a first mode of operation, the optical test instrument is configured to provide an image of the endface of a fiber optic connector under test. In a second mode of operation, the optical test instrument is configured to measure power or power loss in an optical fiber under test. In that regard, the fiber optic connector only has to be coupled to a single port of an optical test instrument for a visual inspection of an endface of a fiber optic connector and a power test of the optical fiber under test.

An embodiment optical test circuit includes a first optical circuit and a second optical circuit formed on a substrate, an input optical waveguide optically connected to the first optical circuit and the second optical circuit, and an output optical waveguide optically connected to the first optical circuit and the second optical circuit. The optical test circuit also includes a light emitting diode optically connected to the input optical waveguide, and a photodiode optically connected to the output optical waveguide.

An inspecting device has an optical switch selectively coupling a light source unit with each of light input/output ports; a first light detecting unit detecting a first intensity of test light input from an inspecting device on a counterpart side and passing through the optical switch; a second light detecting unit detecting a second intensity of the test light directed from the light source unit toward the optical switch; a third light detecting unit optically coupled to another end of a test optical fiber having one end connected to each of the plurality of light input/output ports, and detecting a third intensity of the test light received from the light source unit via the test optical fiber; and an internal loss recording unit recording a loss of an optical path inside the device obtained on a basis of a difference between the third intensity and the second intensity.

Aspects of the present disclosure describe estimating/measuring core-cladding concentricity error in optical fibers. In sharp contrast to the prior art, our inventive method is based on measuring a seemingly unrelated property of fibers called guided acoustic wave Brillouin scattering (GAWBS). As we shall show and describe, by analyzing this GAWBS property we advantageously determine what level of CCCE is exhibited by the optical fiber.

A system for testing an optical fiber includes an optical source apparatus and an optical image sensor apparatus. The optical source apparatus includes a fiber optic connector that connects to a first end of the fiber, and a light emitting device which emits light into the first end of the fiber. The optical image sensor apparatus includes a fiber optic connector that connects to a second end of the fiber, an image sensor that receives light output from the second end of the fiber and generates corresponding image data, a lens array in an optical path between the fiber optic connector and the image sensor, and a processor coupled to the image sensor. The processor, in operation, determines a set of two-dimensional positions based on the image data output from the image sensor, and determines a test result based on the set of two-dimensional positions.

An optical fibre assembly comprises a hollow core optical waveguide comprising a hollow core surrounded by a structured arrangement of longitudinally extending capillaries providing an inner cladding surrounded by an outer cladding; a diagnostic solid core optical waveguide comprising a solid core surrounded by a cladding, and extending substantially parallel to the hollow core optical waveguide; and a jacket surrounding both the hollow core optical waveguide and the solid core optical waveguide and forming a common mechanical environment for the hollow core optical waveguide and the solid core optical waveguide. The optical fibre assembly may be or may comprise or be included in an optical fibre cable, and may be used in a method for testing hollow core optical waveguides.

Beam combining optical systems include a fiber beam combiner having multiple inputs to which output fibers of laser diode sources are spliced. Cladding light stripping regions are situated at the splices and include exposed portions of fiber claddings that are at least partially encapsulated with an optical adhesive or a polymer. A beam combiner fiber that is optically downstream of a laser source has an exposed cladding secured to a thermally conductive support with a polymer or other material that is index matched to the exposed cladding. This construction permits attenuation of cladding light propagating toward a beam combiner from a splice.

A mode-dependent loss measurement device according to an embodiment of the present disclosure measures a mode-dependent loss of a measurement target optical fiber including a coupled MCF. The device includes a light source, a light receiver, mode coupled state change means, and an analysis unit. The light source inputs light to an input end of an excitation optical fiber including another coupled MCF. The light receiver detects a sum of powers of outputted light beams from a plurality of core end faces positioned on an output end of the measurement target optical fiber. The mode coupled state change means changes a mode coupled state of the excitation optical fiber. The analysis unit obtains a mode-dependent loss of the measurement target optical fiber from variations in optical powers detected by the light receiver.