Abstract: A light sampling measurement apparatus comprising a nonlinear optical element supplied with a light to be measured and a sampling light and a light receiving element for receiving a light outputted from the nonlinear optical element, includes: a storage unit for previously storing noise generated in the light receiving element; a calculating unit for obtaining a subtracted noise by subtracting the noise stored in the storage unit, from a measured noise, to calculate a Q value of the light to be measured.

Abstract: The optical sampling measurement introduces an object light ejected from a light source and a sampling pulse light ejected from an active mode-locked fiber laser into a non-linear optical device, thereby to perform an equivalent time sampling of the object light. A signal, which is obtained by receiving a summed frequency light ejected from the non-linear optical device, at a photoreceiver, is fed back so that the repetition frequency of the active mode-locked fiber laser is controlled by a controller.

Abstract: An electro-optic sampling apparatus is provided to enable measurement on potentials of signals on the conductor of coaxial cable with high precision and with ease. Herein, an electric input connector inputs a measured electric signal, which is introduced to a conductive path such as a microstrip line. An electro-optic material (e.g., Bi12SiO20) that provides electro-optic effect such as Pockel's effect is fixed to a bare portion of the conductive path and is varied in birefringence ratio in response to strength of electric field caused by the conductive path through which the measured electric signal transmits. The conductive path is then terminated by a terminal device. Now, a laser beam is radiated toward the electro-optic material, wherein it is varied in polarization in response to variations of the birefringence ratio. Then, the laser beam is reflected by a dielectric mirror and is separated into two beams by a polarization beam splitter.

Abstract: A light sampling measurement apparatus comprising a nonlinear optical element supplied with a light to be measured and a sampling light and a light receiving element for receiving a light outputted from the nonlinear optical element, includes: a storage unit for previously storing noise generated in the light receiving element; a calculating unit for obtaining a subtracted noise by subtracting the noise stored in the storage unit, from a measured noise, to calculate a Q value of the light to be measured.

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: An electro-optic sampling oscilloscope (or EOS oscilloscope) uses an electro-optic probe containing an electro-optic crystal, which is placed under effect of an electric field caused by a measured signal. Laser pulses are supplied to the electro-optic crystal wherein they are subjected to polarization. Then, measurement data representative of a waveform of the measured signal are produced in response to polarization states of the laser pulses and are stored in a measurement data storage. A user can select specific measurement data by using a list of files of multiple measurement data which is displayed on a screen. Then, the EOS oscilloscope displays an outline waveform which is created based on a reduced number of sample points extracted from the selected measurement data. Comments and/or measurement conditions can be stored in the measurement data storage in relation to the measurement data, so that they are adequately displayed on the screen.

Abstract: Pins of an integrated circuit are provided with timing axis signals for testing in the time axis without discrepancies. An electro-optic probe in proximity to a plurality of contact points of a device under test uses positions of equal distance or a pre-set distance as skew measurement points, and detects timing axis signals on each microstrip line, A phase detector detects the phase of the timing axis signals that the electro-optic probe detects, and a phase difference calculator finds the phase difference between the phase detected by the phase detector and a reference value. Phase control of the timing axis signals is carried out by a phase controller so as to cancel the obtained phase difference.

Abstract: In a light receiving circuit for use in electro-optic sampling oscilloscope which receives first and second optical, photodiodes 51 and 52 are connected in series between a positive bias power supply 50P and a negative bias power supply 50N. The photodiodes 51 and 52 receive optical signals whose polarization state correspond to the voltage of a signal to be measured and convert the thus-received optical signals into electric signals. An amplifier 53 amplifies an electric current appearing in a point of connection P between the photodiodes 51 and 52. A current monitor 54 detects the electric signal converted by the photodiode 51, and a current monitor 57 detects the electric signal converted by the photodiode 52. The electric signal detected by the current monitor 54 is subjected to analog-to-digital conversion by an analog-to-digital converter 55, and the electric signal detected by the current monitor 57 is subjected to analog-to-digital conversion by an analog-to-digital converter 58.

Abstract: The present invention relates to an electro-optic sampling oscilloscope. The delay circuit in the electro-optic sampling oscilloscope comprises a delay time detecting circuit, a regulation time determining circuit, a counter circuit and a delay regulating circuit. The delay time detecting circuit detects in the trigger signal a value corresponding to the delay time of a reference clock from a reference clock generating circuit. The regulation time determining circuit determines a regulation time based on the value detected by the delay time detecting circuit so that the regulation time is an integer multiple of the reference clock. The counter circuit is triggered by the trigger signal to count the reference clock through a specific value. The delay regulating circuit employs a signal related to the regulation time from the regulation time determining circuit, to delay the signal output from the counter circuit by the regulation time.

Abstract: The electro-optic probe of the present invention comprises a laser diode for emitting a laser beam in accordance with a control signal from a measuring instrument main body, an electro-optic element, provided with a reflection film on the end surface thereof, a separator provided between the laser diode and electro-optic element, which is pervious the laser beam emitted from the laser diode and separates a beam reflected from the reflection film, two photodiodes which transform the beam reflected by the separator, and a glass plate used for protecting the electro-optic element.

Abstract: The present invention relates to an electro-optic sampling oscilloscope which carries out measurement of a measured signal using an optical pulse generated based on a timing signal from a timing generation circuit. The timing generation circuit includes a frequency measurement circuit which generates a gate signal for a gate interval which is a specified multiple N of the cycle of the desired sampling rate, and counts the input trigger signals during the gate interval of the gate signal; a division circuit which divides the count value of said frequency measurement circuit by the specified multiple N, and determines a divider ratio; and a frequency divider which divides the trigger signals by the divider ratio determined by the division circuit, and outputs the result as the timing signal.

Abstract: Disclosed is a probe signal outputting apparatus which comprises an electrooptic probe for receiving an optical output from a light source and outputting a first optical signal and a second optical signal which are polarized in accordance with a voltage of a to-be-probed signal from an object to be measured; a first photoelectric converting element and a second photoelectric converting element, connected in series between a first bias power supply and a second bias power supply, for respectively receiving the first optical signal and the second optical signal and converting the first and second optical signals to electric signals; an output circuit for outputting an electric signal acquired at a connection node between the first photoelectric converting element and the second photoelectric converting element to a measuring circuit; an adder for adding voltage values equivalent to currents respectively flowing in the first photoelectric converting element and the second photoelectric converting element; and a

Abstract: Disclosed is a probe signal outputting apparatus comprising an electrooptic probe for receiving an optical output from a light source and outputting a first optical signal and a second optical signal which are polarized in accordance with a voltage of a to-be-probed signal from an object to-be-probed; a first photoelectric converting element and a second photoelectric converting element, connected in series between a first bias power supply and a second bias power suppl, for respectively receiving the first optical signal and the second optical signal and converting the first and second optical signals to electric signals; an output circuit for outputting an electric signal acquired at a connection node between the first photoelectric converting element and the second photoelectric converting element; a current drive circuit, provided in an optical input/output unit together with the first photoelectric converting element, the second photoelectric converting elements and the output circuit, for supplying a dr

Abstract: The present invention relates to an electro-optic sampling oscilloscope. This electro-optic sampling oscilloscope carries out measurement of measured signal by using an optical pulse generated based on a timing signal generated from a timing generation circuit synchronous with a trigger signal, providing: a timing generation circuit comprising a fast ramp circuit that outputs a ramp waveform using said trigger signal as a trigger, a slow ramp circuit that increases stepwise and sequentially the output value according to said timing signal; a comparator circuit that compares the output of said fast ramp circuit and the output of said slow ramp circuit and outputs the results of this comparison; and a gate circuit that limits the output of said comparator circuit by closing a gate only when the output of said comparator circuit is unstable based on the input trigger signal and timing signal.

Abstract: The present invention relates to an electro-optic sampling oscilloscope in which an electric field generated by a signal to be measured is coupled with an electro-optic crystal, and an optical pulse outputted from an optical pulse output circuit is caused to enter the electro-optic crystal, and the waveform of the signal to be measured is observed using the polarization state of the optical pulse. The optical pulse output circuit has as the input light thereof a sample optical pulse amplified by an optical amplifier circuit, and outputs, as an optical pulse, the output from an optical filter which blocks the propagation of the spontaneously emitted light of the optical amplifier circuit.

Abstract: An electro-optic sampling oscilloscope (or EOS oscilloscope) is designed to perform measurement such that an electro-optic sampling probe (i.e., EOS probe) is brought into contact with a measured circuit. Optical pulses are input to the EOS probe, wherein they are varied in polarization states in response to the measured circuit. Then, an electric signal output from the EOS probe is amplified to produce a receiving light signal. The receiving light signal is subjected to sampling operations using a first pulse signal to produce detection data, while it is also subjected to sampling operations using a second pulse signal to produce noise data. Herein, the first pulse signal consists of pulses which emerge in synchronization with the optical pulses respectively, while the second pulse signal delays from the first pulse signal by a prescribed delay time. Then, measurement data are produced by subtracting the noise data from the detection data.

Abstract: An electro-optic sampling oscilloscope facilitates adjustment of signal-to-noise ratio caused by electrical, optical and temperature factors.

Abstract: A signal processing circuit is provided for an electro-optic probe, which is used to perform testing of a printed-circuit board of high-speed processing. When laser beams are incident on the electro-optic probe which is brought into contact with the printed-circuit board, they are changed in polarization and are then converted to electric signals. The electric signals are amplified and are then subjected to analog-to-digital conversion to produce digital data. The laser beams (or optical pulses) are generated based on sampling pulses used for sampling of the analog-to-digital conversion. Herein, the sampling pulses are created based on a sweep signal and a step-like signal. The sweep signal increases in level with a certain slope and then decreases suddenly in one period of a trigger pulse signal. The step-like signal increases in level in a step-like manner, wherein it is increased by a predetermined level in response to each of the sampling pulses.