An optical fiber testing device (300) being plugged into a port at which optical signals including communication and test signals within different wavelength bands being received, comprises an optical connector (304) including a plug body surrounding a ferrule holding an optical fiber (301) and a reflector component (326) carried with the optical connector (304). The reflector component (326) is optically coupled to the rear of the optical fiber and reflects the test signal. A method for testing an optical fiber, comprises removably securing a reusable ruggedized optical fiber testing device to a ruggedized port of an optical fiber terminal to optically couple to an optical fiber under test, transmitting a test signal over the optical fiber under test, and using the reflector component to return the test signal over the optical fiber under test when receiving the test signal.

Provided is a special optical fiber for measuring a 3D curved shape, and a system for measuring the 3D curved shape by using a special optical fiber. The special optical fiber comprises: an optical fiber core for transmitting an optical signal; an inner cladding covering the optical fiber core; and an outer cladding covering the inner cladding. In particular, the refractive index (n1) of the optical fiber core, the refractive index (n2) of the inner cladding, and the refractive index (n3) of the outer cladding are set in a relationship of n1≥n3>n2. The inner cladding covering the optical fiber core has a cut portion in the longitudinal direction. The optical fiber core is exposed through the cut portion. In addition, the cut portion is filled with a material having the same refractive index as the optical fiber core or the outer cladding.

There is provided a technique to reduce the Rayleigh coherence noise in OTDR measurements using spectral averaging of OTDR traces while at least partly cancelling chromatic dispersion pulse broadening on the averaged OTDR trace by applying a chromatic dispersion correction prior to averaging the OTDR traces. By correcting for chromatic dispersion pulse broadening, it allows to reduce the Rayleigh coherence noise without impacting the OTDR spatial resolution.

A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the input optical beam into a first optical beam and a second optical beam. The system may also include an optical configuration, which may determine an optical beam path associated with the first optical beam and the second optical beam, transmit the first optical beam in a first direction along the optical beam path and transmit the second optical beam in a second direction along the optical beam path.

According to examples, a system for measuring polarization dependent loss (PDL) for a device-under-test (DUT) may include a tunable laser, a polarization element and a power meter. The tunable laser may emit an optical signal to sweep across an optical band at a constant rate. The polarization element may scramble polarizations states of the optical signal emitted from the tunable laser. The power meter may take power measurements associated with the optical signal emitted from the tunable laser, wherein the power measurements from the power meter are used to determine a maximum insertion loss (IL) and a minimum insertion loss (IL) associated with the device-under-test (DUT). An average insertion loss (IL) and a polarization dependent loss (PDL) for the device-under-test (DUT) may be calculated based on the maximum insertion loss (IL) and the minimum insertion loss (IL) associated with the device-under-test (DUT).

An object of the present disclosure is to enable each inter-modal coupling efficiency at a connection point between few-mode optical fibers to be accurately acquired. The present disclosure involves: inputting pulsated pump light in a fundamental mode or a first higher-order mode into one end of an optical fiber under test constructed by connecting two optical fibers in series; inputting probe light having an optical frequency difference within a Brillouin frequency shift range with respect to the pump light into the other end of the optical fiber under test in the fundamental mode or the first higher-order mode; measuring a Brillouin gain distribution related to a distance of transmitted light intensity of probe light output from the one end into which the pump light was input; acquiring a transmittance at a connection point of the optical fiber under test by using the Brillouin gain distribution; and substituting the transmittance and a Brillouin gain coefficient unique to the optical fiber under test into an expression representing a transmittance at the connection point that occurs in a Brillouin gain distribution in each mode and solving a simultaneous equation to calculate each inter-modal coupling efficiency at the connection point.

An optical fiber characteristic measurement device (1, 2, 3) includes a photodetector (15, 15A) which detects Brillouin scattered light (LS) obtained by causing light to be incident on an optical fiber (FUT), an intensity acquisitor (16, 16A) which acquires a signal intensity at a prescribed reference frequency (f1, f2) from a detection signal (S1, S2, S3) output from the photodetector, and a measurer (18, 18A, 18B) which measures characteristics of the optical fiber by obtaining a peak frequency of a Brillouin gain spectrum, which is a spectrum of the Brillouin scattered light, from the signal intensity at the reference frequency acquired by the intensity acquisitor.

A system for providing information based on a spectral content of an optical signal, comprises: an optical modulator for applying a time-dependent modulation to the optical signal according to at least one sub-optical modulation frequency, to provide a modulated optical signal. The system also comprises an optoelectronic device configured for receiving the modulated optical signal and responsively generate an electrical sensing signal, and a signal processing system configured for processing the electrical sensing signal and to generate output correlative to at least one wavelength of the optical signal based on the modulation.

An optical fiber connection state determination system determines a state of connection between a first optical fiber configured to propagate a test light input from a light source and a second optical fiber in a connector configured to detachably connect an output side from which the test light is output in the first optical fiber and an input side of the second optical fiber to which the test light propagated by the first optical fiber and output from the first optical fiber is input, and includes: a measurement unit configured to measure an intensity of a reflected light reflected and propagating thorough the first optical fiber in the test light; and a determination unit configured to determine the state of connection between the first optical fiber and the second optical fiber in the connector based on the intensity measured by the measurement unit.

Provided are a fisheye camera calibration system, method and an electronic device. The system includes a hemispherical target, a fisheye camera and an electronic device. The hemispherical target includes a hemispherical inner surface and multiple markers provided on the hemispherical inner surface. The fisheye camera is used for photographing the hemispherical target and acquiring a target image, where the hemispherical target and the multiple markers provided on the hemispherical inner surface are captured in the target image. The electronic device is used for acquiring initial values of k.sub.1, k.sub.2, k.sub.3, k.sub.4, k.sub.5, u.sub.0, v.sub.0, m.sub.u and m.sub.v, and using a Levenberg-Marquardt algorithm to optimize the initial values of k.sub.1, k.sub.2, k.sub.3, k.sub.4, k.sub.5, u.sub.0, v.sub.0, m.sub.u and m.sub.v, so as to determine imaging model parameters of the fisheye camera.