Abstract: An apparatus and method for accurate measurement of characteristics of optical fibers (distribution of polarization mode dispersion and distribution of magnitude of birefringence). Pulse light is inputted to a subject optical fiber, back scattered light of the pulse light from the subject optical fiber is detected by a photodetector to find a Stokes vector, and polarization mode dispersion in a longitudinal direction is measured. The apparatus comprises a light source unit for outputting the pulse light having at least three different angular frequencies, and an arithmetic operation unit for calculating the magnitude of linear polarization components and the magnitude of a circular polarization component of a polarization dispersion vector on the basis of the Stokes vector and thus calculating polarization mode dispersion.

Abstract: An apparatus and method for measuring characteristics of optical fibers that enable accurate measurement of characteristics of optical fibers (distribution of polarization mode dispersion and distribution of magnitude of birefringence) are to be realized. This invention is an improvement of an optical fiber characteristics measuring apparatus in which pulse light is inputted to a subject optical fiber, back scattered light of the pulse light from the subject optical fiber is detected by a photodetector to find a Stokes vector, and polarization mode dispersion in a longitudinal direction is measured. The apparatus comprises a light source unit for outputting the pulse light having at least three different angular frequencies, and an arithmetic operation unit for calculating the magnitude of linear polarization components and the magnitude of a circular polarization component of a polarization dispersion vector on the basis of the Stokes vector and thus calculating polarization mode dispersion.

Abstract: A phase delay characteristic measuring apparatus includes an in-phase component calculating means for outputting a correlation value between input sampling data of the input signal and the output signal and ideal sine waveform data as a baseband I signal (in-phase component), a quadrature component calculating means for outputting a correlation value between the input sampling data of the input signal and the output signal and ideal cosine waveform data as a baseband Q signal (quadrature component), a phase angle calculating means for outputting phase angles of the input signal and the output signal based on the baseband I signal and the baseband Q signal, and a phase delay calculating means for calculating an amount of phase delay of the tested device from the phase angles of the input signal and the output signal.

Abstract: A phase delay characteristic measuring apparatus includes an in-phase component calculating means for outputting a correlation value between input sampling data of the input signal and the output signal and ideal sine waveform data as a baseband I signal (in-phase component), a quadrature component calculating means for outputting a correlation value between the input sampling data of the input signal and the output signal and ideal cosine waveform data as a baseband Q signal (quadrature component), a phase angle calculating means for outputting phase angles of the input signal and the output signal based on the baseband I signal and the baseband Q signal, and a phase delay calculating means for calculating an amount of phase delay of the tested device from the phase angles of the input signal and the output signal.

Abstract: A peak detecting device which can efficiently detect a peak of an analog signal in a smaller error for a short time without making a sampling frequency higher. The analog signal processing apparatus (1) as the peak detecting device comprises: the frequency-dividing ratio setting device (2) for outputting the frequency-dividing ratio setting signal (2a); the frequency divider (3) for frequency-dividing the frequency of the reference clock signal (1b) by the frequency-dividing ratio which is changed by the frequency-dividing ratio setting signal (2a), to generate the sampling clock signal (3a); the A/D converter (4) for carrying out the sampling of the analog input signal (1a) at the clock timing which is synchronized with the sampling clock signal (3a); the sampling data memory (5) for memorizing the digital data (4a) which are obtained by sampling by the A/D converter (4); and the data processor (6) for reading out the digital data (4a) as the digital data (5a), to determine the peak of the digital data (5a).

Abstract: A health pillow which emits the fragrance of wood and induces a pleasant mood leading to peaceful sleep. A plurality of cylindrical, hollow wood sections improve air circulation in the pillow while at the same time emitting a fragrance which lasts for a long time. Wooden sheets which include a plurality of half-cylindrical shaped pieces are fastened together to form a sheet of wooden tubes. This sheet is cut into individual tubes which are cut into pieces ranging in length from several millimeters to fifteen to sixteen millimeters, thus producing numerous small tubular pieces of wood. These small tubular pieces of wood are used to fill the interior of the pillow.