摘要:
An optical branching device comprising: a substrate; a first core member formed on the substrate, having a first edge face; a second core member formed on the substrate, tapering toward the first edge face of the first core member, having a second edge face facing the first edge face at a given space; and a third core member formed on the substrate, tapering toward the first edge face of the first core member, having a third edge face facing the first edge face at a given space.
摘要:
An optical branching device according to present invention comprises a cladding member, a first core member, a second core member, and a third core member. These core members are isolated each other, and the with of a edge face of the first core member is greater than total length of the widths of second and third core members terminals facing to the first core member and a gap between the second and third core members.
摘要:
The present invention comprises a waveguide substrate and an optical waveguide disposed on the substrate, the optical waveguide having an optical waveguide region as a light transmission path, an insertion region for inserting an optical functional component having a mode field width of light propagating therein larger than that of light propagating in the optical waveguide region, and an optical connection region provided between the optical waveguide region and the insertion region to change a mode field width of light propagating therein.
摘要:
The present invention relates to a multicore optical fiber having a structure for effectively inhibiting polarization mode dispersion from increasing, and the multicore optical fiber comprises a plurality of multicore units and a cladding region integrally covering the plurality of multicore units while separating the multicore units from each other. Each of the plurality of multicore units includes a plurality of core regions arranged such as to construct a predetermined core arrangement structure on a cross section orthogonal to an axis. The core arrangement structure of each multicore unit on the cross section has such a rotational symmetry as to coincide with the unrotated core arrangement structure at least three times while rotating by 360° about a center of the multicore unit, thereby reducing the structural asymmetry of each multicore unit. This lowers the structural birefringence in each multicore unit, thereby inhibiting the polarization mode dispersion from increasing in the multicore optical fiber.
摘要:
The present invention relates to an optical fiber characteristic distribution sensor comprising a structure to effectively reduce the measurement errors of position in the temperature distribution measurement etc. The sensor comprises an optical fiber section, part of which is installed in an object to be measured and to which probe light and pumping light are inputted in opposite directions. The optical fiber section includes a marker portion where data relating to the shape of a BGS in the maker has been preliminarily measured in a state where the optical fiber section is installed in a normal state. At the time of calculating the characteristic distribution in the longitudinal direction of the optical fiber section while measuring the data relating to the BGS shape, the errors of the calculated gain occurrence position are corrected, for example, by shifting the scanning range of phase difference between the probe light and the pumping light. The amount of shift of the scanning range of phase difference is given based on a difference value between the phase difference at the time of measurement when the BGS that reflects the gain that has occurred in the marker portion is measured, and the reference phase difference when data relating to the already known shape of the BGS in the marker portion has been preliminarily measured.
摘要:
The present invention relates to an optical communications system equipped with a structure, capable of applying a PBGF as an optical transmission line, by which high capacity information transmission is enabled by use of the PBGF. The optical communications system (1) is provided with an optical transmitter (10), an optical receiver (20) and an optical transmission line (30). The optical transmitter (10) outputs signal light, whose phase or optical frequency is modulated, into the optical transmission line (30). The optical transmission line (30) transmits the signal light outputted from the optical transmitter (10) to the optical receiver (20). The optical receiver (20) receives the signal light transmitted from the optical transmitter (10) via the optical transmission line (30). The optical transmission line (30) includes a photonic band gap fiber having a hollow core.
摘要:
The present invention relates to an optical fiber distribution type detecting method and the like equipped with a structure for enabling efficient measurement of a temperature distribution or strain distribution. This method regulates a modulation frequency and modulation index for probe light and pumping light opposingly incident on an object from a light source and a phase difference between the probe light and pumping light, thereby successively setting the length and location of search domains in a region to be measured. In particular, a detection process is executed while resetting the search domain length shorter at a predetermined interval of time or when an abnormality is detected. Thus partly changing the distance resolution for a specific region in the course of the detection process enables efficient measurement operations in a short time.
摘要:
The temperature measuring device of the present invention comprises: a light source for outputting light; an optical fiber to which light outputted by the light source is inputted and from which Brillouin scattered light is outputted; a detection unit for detecting a spectrum of the Brillouin scattered light; a judgment unit for judging whether or not a frequency shift of the spectrum of the Brillouin scattered light detected by the detection unit belongs to a specific region in which the rate of change of the frequency shift with respect to the temperature of the optical fiber is smaller than a predetermined value; and an analysis unit for, when the judgment unit judges that the frequency shift does not belong to the specific region, analyzing the temperature in use of the frequency shift, and for, when the judgment unit judges that the frequency shift belongs to the specific region, not performing analysis, or analyzing the temperature in use of at least the linewidth of the spectrum of the Brillouin scattered light detected by the detection means.
摘要:
In the dispersion-compensating system of the present invention, a demultiplexer demultiplexes optical signals in a signal wavelength band of 1520 nm to 1620 nm propagating through a first common transmission line into C band (1520 nm to 1565 nm) and L band (1565 nm to 1620 nm). Then, the demultiplexer outputs the optical signals of C band into a first branched transmission line and the optical signals of L band into a second branched transmission line. A first dispersion-compensating device is provided on the first common transmission line and compensates for the dispersion in C and L bands. A second dispersion-compensating device is provided on the second branched transmission line and compensates for the dispersion in L band, which has not fully been compensated for by the first dispersion-compensating device. Hence, the dispersion of optical transmission line can fully be reduced in a wide signal light wavelength band.
摘要:
The present invention provides an optical fiber enabling signal transmission in a wider band, which is applicable to optical transmission not only in the 1.3 μm wavelength band but also in the 1.55 μm wavelength band, as a transmission medium of a WDM optical communication system capable of transmitting signal light of multiple channels. The optical fiber is comprised of silica glass and has a core region along a predetermined axis and a cladding region provided on the outer periphery of the core region. The optical fiber comprising such a structure has, as the following typical optical characteristics, a cable cutoff wavelength of 1260 nm or less, a transmission loss of 0.32 dB/km or less at the wavelength of 1310 nm, and an OH-related loss increase of 0.3 dB/km or less at the wavelength of 1380 nm.