Abstract: An airway adapter includes an airway adapter body including a first tube connection portion, a second tube connection portion, and a detection portion provided between the first tube connection portion and the second tube connection portion, and a support base configured to support the airway adapter body. The support base is configured to support the first tube connection portion at a position higher than a position of the second tube connection portion.

Abstract: A display device includes a display unit including a plurality of pixels to cause the pixels to emit light to provide an image to a user; a drive control unit configured to move the display unit at predetermined intervals; and a timing setting unit configured to set an emission timing of the light for each of the pixels based on a position of the display unit.

Abstract: An X-ray tube billing system for a fluoroscopic apparatus for non-destructive inspection configured to perform X-ray fluoroscopy on a subject using an X-ray tube includes a fluoroscopy time detector configured to detect a length of time during which the X-ray fluoroscopy has been performed using the X-ray tube, and a billing amount calculator configured to calculate a billing amount related to use of the X-ray tube based on the length of time during which the X-ray fluoroscopy has been performed, which is detected by the fluoroscopy time detector.

Abstract: A head-mounted display according to the present embodiment includes a combiner which is aspherical, arranged in front of a user, and configured to reflect display light for forming a display image toward the user, and a beam splitter which is arranged between the combiner and the user, and configured to reflect the display light to the combiner and transmit display light reflected by the concave mirror. In an optical system, in a range outside the effective viewing angle, the distortion exceeds 5% and increases toward an outside of a viewing field.

Abstract: An X-ray tube billing system for a fluoroscopic apparatus for non-destructive inspection configured to perform X-ray fluoroscopy on a subject using an X-ray tube includes a fluoroscopy time detector configured to detect a length of time during which the X-ray fluoroscopy has been performed using the X-ray tube, and a billing amount calculator configured to calculate a billing amount related to use of the X-ray tube based on the length of time during which the X-ray fluoroscopy has been performed, which is detected by the fluoroscopy time detector.

Abstract: Provided is a head-mounted display that allows a user to see an outside view properly. The head-mounted display includes a combiner configured to combine display light for forming a display image with outside light from in front of a user wearing a head-mounted display, and a light reducing unit configured to transmit a part of outside light from below the combiner and have transmittance equal to or lower than transmittance of the combiner.

Abstract: A relay lens system forms an image displayed on an image display unit as an intermediate image. A luminous flux of the image emitted from the relay lens system reflected by a half mirror is incident to a curved combiner, and the combiner reflects the incident luminous flux to the half mirror to enable an observer to observe a virtual image through the half mirror. The relay lens system forms the intermediate image at an intermediate image forming position on an optical axis before a light reflected by the half mirror is incident to the curved combiner. The distance from the optical axis of the curved combiner to a light emission surface of the relay lens system is shorter than or equal to the distance from the optical axis of the curved combiner to a maximum reflection position.

Abstract: A measurement method for measuring an effective refractive index difference between two propagation modes of a multimode fiber is provided. The method includes: measuring a first Brillouin frequency shift ?1 by specifying a frequency having a lowest-frequency peak out of peaks in a first frequency spectrum of scattered light in a first propagation mode; measuring a second Brillouin frequency shift ?2 by specifying a frequency having a lowest-frequency peak out of peaks in a second frequency spectrum of scattered light in a second propagation mode; and calculating an effective refractive index difference ?neff in accordance with ?neff=(?1??2)/(2kVL) with use of the first Brillouin frequency shift ?1, the second Brillouin frequency shift ?2, a predetermined wave number k of light in a vacuum, and a predetermined constant VL.

Abstract: A relay lens system forms an image displayed on an image display unit as an intermediate image. A luminous flux of the image emitted from the relay lens system reflected by a half mirror is incident to a curved combiner, and the combiner reflects the incident luminous flux to the half mirror to enable an observer to observe a virtual image through the half mirror. The relay lens system forms the intermediate image at an intermediate image forming position on an optical axis before a light reflected by the half mirror is incident to the curved combiner. The distance from the optical axis of the curved combiner to a light emission surface of the relay lens system is shorter than or equal to the distance from the optical axis of the curved combiner to a maximum reflection position.

Abstract: A measurement method for measuring an effective refractive index difference between two propagation modes of a multimode fiber is provided. The method includes: measuring a first Brillouin frequency shift v1 by specifying a frequency having a lowest-frequency peak out of peaks in a first frequency spectrum of scattered light in a first propagation mode; measuring a second Brillouin frequency shift v2 by specifying a frequency having a lowest-frequency peak out of peaks in a second frequency spectrum of scattered light in a second propagation mode; and calculating an effective refractive index difference ?neff in accordance with ?neff=(v1?v2)/(2kVL) with use of the first Brillouin frequency shift v1, the second Brillouin frequency shift v2, a predetermined wave number k of light in a vacuum, and a predetermined constant VL.

Abstract: A test pulse is generated from a first and a second test light beam pulse with different wavelengths, with a predetermined time difference applied between the first and the second test light beam pulse. A circulator inputs the test pulse to a trunk fiber of a measurement target fiber line. A reflected light is extracted which is output from an input end of the trunk fiber. A filter extracts stimulated Brillouin backscattered light. A receiver receives and converts the scattered light into an electrical signal. A processing device carries out the signal to determine in which of N branched fibers the stimulated Brillouin scattered light is generated, while varying a time difference between the first and the second test pulse.

Abstract: A test pulse is generated from a first and a second test light beam pulse with different wavelengths, with a predetermined time difference applied between the first and the second test light beam pulse. A circulator inputs the test pulse to a trunk fiber of a measurement target fiber line. A reflected light is extracted which is output from an input end of the trunk fiber. A filter extracts stimulated Brillouin backscattered light. A receiver receives and converts the scattered light into an electrical signal. A processing device carries out the signal to determine in which of N branched fibers the stimulated Brillouin scattered light is generated, while varying a time difference between the first and the second test pulse.

Abstract: Light to be measured L and sampling pulse light LSP are each split into M beams, and a time delay of 0, T, 2T, . . . , (M?1)T is given to each of the M-split sampling pulse light beams. The M-split light beams to be measured are then respectively multiplexed with M optical 90-degree hybrids, and M electrical field amplitudes per time T are determined for the light beam to be measured, based on M sets of output currents received at a balance light receiving element that receives light emitted from each of the optical 90-degree hybrids. The amplitudes of the respective wavelength optical signals contained in the light beam to be measured are calculated through Fourier transformations of the field electrical amplitudes. Pulsed light with a spectral width that covers the total frequency bandwidth of the light to be measured is used as the sampling pulse light.

Abstract: An object of the invention is to provide an optical reflectometry and an optical reflectometer, in which accurate measurement can be performed irrespective of a measurement distance. In the optical reflectometry and optical reflectometer according to the invention, in which a distribution of backscattered light intensity from a measurement target in an optical propagation direction is measured using Optical Frequency Domain Reflectometry (OFDR), a coherence monitor unit 12 that monitors a coherence property of a frequency sweep light source 1 is provided, and measurement result of a measuring unit 11 is corrected based on the monitor result of the coherence monitor unit 12.

Abstract: Light to be measured L and sampling pulse light LSP are each split into M beams, and a time delay of 0, T, 2T, . . . , (M?1)T is given to each of the M-split sampling pulse light beams. The M-split light beams to be measured are then respectively multiplexed with M optical 90-degree hybrids, and M electrical field amplitudes per time T are determined for the light beam to be measured, based on M sets of output currents received at a balance light receiving element that receives light emitted from each of the optical 90-degree hybrids. The amplitudes of the respective wavelength optical signals contained in the light beam to be measured are calculated through Fourier transformations of the field electrical amplitudes. Pulsed light with a spectral width that covers the total frequency bandwidth of the light to be measured is used as the sampling pulse light.

Abstract: The invention is to provide a wavelength dispersion measuring method for an optical fiber capable of measuring a wavelength dispersion in a section extending from an incident end of the optical fiber to an arbitrary point along the way by using a scattering phenomenon in which a scattering coefficient at a local point on the optical fiber is independent of time. Incident light having a known spectral density function S(?) is caused to be incident on the optical waveguide, and a wavelength dispersion of the section extending from the incident end of the optical waveguide to the arbitrary point along the way by a correlational function between a signal being proportional to a scattered light amplitude generated at a first halfway point and a signal being proportional to a scattered light amplitude generated at a second halfway point.

Abstract: An object of the invention is to provide an optical reflectometry and an optical reflectometer, in which accurate measurement can be performed irrespective of a measurement distance. In the optical reflectometry and optical reflectometer according to the invention, in which a distribution of backscattered light intensity from a measurement target in an optical propagation direction is measured using Optical Frequency Domain Reflectometry (OFDR), a coherence monitor unit 12 that monitors a coherence property of a frequency sweep light source 1 is provided, and measurement result of a measuring unit 11 is corrected based on the monitor result of the coherence monitor unit 12.

Abstract: The invention is to provide a wavelength dispersion measuring method for an optical fiber capable of measuring a wavelength dispersion in a section extending from an incident end of the optical fiber to an arbitrary point along the way by using a scattering phenomenon in which a scattering coefficient at a local point on the optical fiber is independent of time. Incident light having a known spectral density function S(?) is caused to be incident on the optical waveguide, and a wavelength dispersion of the section extending from the incident end of the optical waveguide to the arbitrary point along the way by a correlational function between a signal being proportional to a scattered light amplitude generated at a first halfway point and a signal being proportional to a scattered light amplitude generated at a second halfway point.

Abstract: There is disclosed an optical pickup device including: a blue semiconductor laser which emits a first laser light having a wavelength of 450 nm or less to record on or reproduce from an extra-high density optical disc; a red semiconductor laser which emits a second laser light having a wavelength longer than that of the first laser light to record on or reproduce from a DVD having a low recording density; an objective lens; and an aberration correction element. The objective lens is designed for the extra-high density optical disc, and has a numerical aperture (NA) of 0.75 or more. The aberration correction element passes the first laser light as such and thereafter allows the light to be incident upon the objective lens, whereas the element limits an aperture with respect to the second laser light and diffracts the second laser light so as to correct an aberration with respect to the DVD and thereafter allows the light to be incident upon the objective lens.

Abstract: The optical sampling system performs by detecting the interference effect which is a linear correlation between the signal lights and the optical pulses, so that both the signal lights and the optical pulses can have relatively low intensities, and the reception sensitivity is high. Also, the pulse width of the optical pulses and the amount of delay given to the optical pulses are the only factors that limit the time resolution, so that it is possible to provide the optical sampling system with excellent time resolution and power consumption properties, and it is possible for the optical sampling system to monitor not only the intensity of the signal lights but also the frequency modulation component as well.