Abstract: Plane diffraction grating 13 is formed of a material having an appropriate linear expansion coefficient and a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of members other than plane diffraction grating 13 is cancelled out or reduced by a variation in the wavelength of the reflected light from concave mirror 14 on account of thermal expansion or shrinkage of plane diffraction grating 13. The same principle is used to deal with the effect on the wavelength of the diffracted light that may be caused by changes in the layout of individual members on account of thermal expansion or shrinkage of substrate 10a that fix them.

Abstract: The data processor 1 converts the serial data in the STM-16 to parallel data that is based on four bytes (32 bits). The transparence data detector 20 detects the position of the data (transparence data) as a candidate for transparence processing in the parallel data and the transparence data sampling section 30 converts the transparence data based on the detected position and rearranges the processed data in each parallel data block (hereinafter referred to as a block). then, the data arrangement section 40 sequentially inserts empty byte data in each block to the preceding block to rearrange parallel data. Thus, the data processor 1 can perform transparence processing easily via a relatively low-speed general-purpose device.

Abstract: A polarization scrambler includes a Faraday element in which the thickness of a direction vertical to an optical axis changes continuously, and a magnetic field generator for generating a magnetic field in a direction of the optical axis with respect to the Faraday element.

Abstract: An AD converter evaluation apparatus evaluates an AD converter, which includes a first programmable power supply, a second programmable power supply, an attenuator circuit, an addition circuit, and a digital multimeter. The first and second programmable power supplies sets a first and second voltages. The attenuator circuit attenuates the first voltage of the second programmable power supply. The addition circuit adds the first voltage of the first programmable power supply and the attenuated voltage of the attenuator circuit. The digital multimeter measures the first voltage of the first programmable power supply and the second voltage of the second programmable power supply. Output voltage of the addition circuit is input to the AD converter.

Abstract: In a four-stage type monochromator, there is provided a returning reflector 6 for making the dispersing direction of the wavelength of light 13e and 13h incident on and emergent from a plane diffraction grating 4 is reversed before and after its reflection. Angles of incident and emergent light at a time when the light is spectrally separated by the diffraction grating 4 are made identical.

Abstract: Techniques for use in sweep synchronization test equipment include receiving a simulation setting and displaying a simulated result based on the simulation setting and previously-measured data. The equipment is switched to a measurement mode in response to user activity, and the simulation setting is used as a control setting. A new measurement is performed based on the control setting. The displayed simulated result is updated based on data obtained from the new measurement.

Abstract: A chromatic dispersion distribution measurement apparatus, comprises: a chromatic dispersion value calculation unit for calculating a plurality of actual chromatic dispersion values in an optical device at a plurality of wavelengths; and a chromatic dispersion interpolation unit for interpolating an expected chromatic dispersion value between the actual chromatic dispersion values calculated by the chromatic dispersion value calculation unit, in order to obtain a chromatic dispersion distribution as a function of wavelength.

Abstract: An SNR calculation method having the steps of measuring the wavelength characteristic of a dynamic range in an optical spectrum measurement apparatus for each wavelength in a multiplexed wavelength range and storing the wavelength characteristic in a storage unit, measuring the signal level and the noise level of a measured optical signal wavelength, reading the noise level of the wavelength of the measured optical signal produced by each of other optical signal wavelengths multiplexed on the measured optical signal wavelength from the storage unit, subtracting the noise level read from the storage unit from the noise level of the measured optical signal wavelength to provide the corrected noise level, and calculating the SNR of the measured optical signal from the measured optical signal level and the corrected noise level.

Abstract: The waveform generating circuit according to the present invention includes a data selector (105) and edge selectors (107, 109). The data selector (105) inputs two data having the same bit number as input data (111, 113) and divides the total bit number (2N) of the inputted two data into two data on a basis of a setting value (&agr;). The edge selector (107) generates in response to a timing edge (117), as an output waveform (119), the waveform corresponding to a first data (115) which is one of the two divided data of the total bit number. The edge selector (109) generates in response to a timing edge (123), as an output waveform (125), the waveform corresponding to a second data (121) which is the other of the two divided data of the total bit number.

Abstract: The optical interferometer in which the incident light beam 3 is branched into 2 optical paths of the reflection light and the transmission light which cross at right angle with each other by the beam splitter 4, and on each optical path, the reflection light is totally reflected by the first reflection unit 5, and the transmission light is totally reflected by the second reflection unit 6, and the reflection lights by both reflection units 5 and 6 are wave-combined again by the beam splitter 4, and received by the light receiver 7. The beam splitter 4 by which the incident light beam is wave-separated and wave-combined, is arranged with a little inclination from the vertical to the incident light beam.

Abstract: An optical spectrum analyzer 100 and a wavelength variable light source 101 have each a sweep synchronization start function. A correction function of the rotation speed of a motor 106 for varying the angle of a diffraction grating in a spectroscope 104 so that extracted wavelength and output signal light wavelength match over a setup sweep wavelength range is found from the output signal light wavelength characteristic relative to the rotation angle of a spectral element 119 and the extracted wavelength of the spectroscope 104, and the rotation angle of motor 106 for driving the spectroscope 104 is varied for each setup wavelength in accordance with the correction function, then sweep is performed.

Abstract: An electro-optic probe has a laser diode for emitting a laser beam in accordance with a control signal from a measuring instrument main body, an electro-optic or magneto-optic element provided with a reflection film on an end surface thereof, a separator provided between the laser diode and electro-optic or magneto-optic element which is pervious the laser beam emitted from the laser diode and separates a beam reflected from the reflection film and two photodiodes which transform the beam reflected by the separator. A member of weak dielectric material, such as a glass plate, overlies the electro-optic or magneto-optic element at the end of the probe to protect the element, or the element is at the end of the probe and is exposed.

Abstract: A wavelength-variable light source apparatus having a wavelength calibration function of emitted light therefrom.

Abstract: In a light wavelength dispersion measuring apparatus 1, three band-pass filters BPa1 to BPa3 are connected in parallel, three band-pass filters BPb1 to BPb3 are connected in parallel, and three phase comparators PCa to PCc are connected in parallel for making it possible to conduct phase difference measurement of the nth-order harmonics (n=1, 4, 8) at the same time, so that a wavelength dispersion calculator 10 can calculate the wavelength dispersion values of the nth-order harmonics (n=1, 4, 8) at the same time. As a result, measurement time of measuring the wavelength dispersion characteristic in the light wavelength dispersion measuring apparatus 1 can be shortened.

Abstract: The present invention allows reducing the power consumption, reducing the amount of heat generation, improving the frequency characteristics, and reducing noise superposition. A control circuit 25 supplies to a control circuit 5 a control signal CS 1 that indicates the setting voltage of a DUT 9 as a control signal CS 8. In addition, the control circuit 25 controls switching power sources 21 and 22 and the polarity control circuits 23 and 24 depending on control signals CS 4 to CS 7 such that the voltage drop amount of the control elements 6 and 7 becomes a value sufficient to operate the control elements 6 and 7 based on a control signal CS 1 and a detected signal DS2 that is fed back from the DUT 9. The control circuit 5 controls the control elements 6 and 7 depending on the control signal CS 8.

Abstract: The transmission error measuring device comprises; a first counting circuit, a test data outputting circuit, a selecting circuit, a multiplexing circuit, a demultiplexing circuit, an arranging circuit, a data array monitoring circuit, a second counting circuit, a reference data outputting circuit, and a comparing circuit. When a test data outputted from the test data outputting circuit does not correspond to a reference data outputted from the reference data outputting circuit, the data array monitoring circuit rearranges the first count value by using a bit set at the bottom thereof in order to rearrange the test data.

Abstract: A wavelength-variable light source apparatus having a wavelength measurement function for measuring the wavelength characteristic of an object to be measured. In the apparatus, a CPU outputs control signals for controlling components of a light power meter section via a bus for controlling a light detection operation. When the CPU obtains light detection level data detected by the light power meter section from light passing through an object to be measured, the CPU stores the light detection level data for each wavelength in the object to be measured in an RAM and causes a display control section to display the light detection level on a display section.

Abstract: A method of measuring a Q-value according to a mean value and standard deviation of a signal level distribution of input data comprises: a first step for calculating a difference between bit error rates of input data sampled by a plurality of threshold values which are a little different from each other; a second step for calculating a difference between the difference data obtained in the first step; and a third step (steps 118 and 120) for calculating a mean value and standard deviation of the signal level of input data when data obtained in the first and the second step (steps 100 to 116) are utilized.

Abstract: An integrated circuit testing apparatus includes a control section 12 including a memory for storing the plurality of testing programs corresponding to the plurality of tests, and a transfer control unit for transferring the plurality of testing programs on the basis of an control command; and an IC testing section 20 including a ROM 24 in which the testing programs transferred from the transfer control means are stored, a RAM 26 in which the test results are temporarily stored, and a processing unit 22 for temporarily storing the test results in the RAM 26 whenever execution of each testing program has been completed, synthesizing all the test results when execution of all the testing programs have been completed to set a final test result for each device to be tested, and sending the final result to the automatic sorter 30.

Abstract: A wavelength-variable light source equipped with a semiconductor laser 1, one end of which is provided with an antireflection coating 1A, is equipped with a power correction filter 10 which permits transmission of the light output from the semiconductor laser 1, thereby rendering the characteristics of the output light substantially flat.