US 7,068,360 B2Granted

Optical sampling waveform measuring apparatus

AssigneeYokogawa Electric Corporation

InventorHiroshi Ohta

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Abstract

In order to provide an optical sampling waveform measuring apparatus which can measure an ultra-high speed optical signal accurately by using a stable, narrow pulse, and a low timing jitter sampling optical pulse, an optical sampling waveform measuring apparatus is provided with a passive mode-locked fiber ring laser for generating a sampling optical pulse and a cavity length varying device which adjusts the cavity length in a passive mode-locked fiber ring laser.

Claims7

Dependent claims

An optical sampling waveform measuring apparatus comprising:

a first electrical signal generator (SG1) for generating electric signals having a cycle frequency fsig;
a mode-locked fiber ring laser (110) which is pumped by the electric pulses P1, the mode-locked fiber ring laser (110) generating optical pulses P6 synchronous with clock signals of the electric pulses P1;
a pattern generator (111) for outputting a predetermined pattern of data signal rows, each of the data signal rows consisting of at least “0” (zero) and “1” (one), the data signal rows being synchronous with the clock signals of the electric pulses P1;
an optical intensity modulator (112) for modulating the optical pulses P6 based on the predetermined pattern, and outputting optical pulses P7;
an optical amplifier (113) for amplifying the optical pulses P7;
a polarization controller (114) for controlling a polarization direction of the optical pulses P7, and outputting optical pulses P8 having the cycle frequency fsig;
a second electrical signal generator (SG2) for generating electric sampling pulses P2 having the cycle frequency (fsig/n−Δf) synchronous with the electric pulses P1;
a passive mode-locked fiber ring laser (1) for emitting optical sampling pulses P10 having the cycle frequency (fsig/n−Δf) which corresponds to the electric sampling pulses P2;
a polarization direction controller (109) for controlling a polarization direction of the optical sampling pulses P10, and outputting optical sampling pulses P4 having the cycle frequency fsig;
a polarization beam splitter (115) for mixing the optical pulses P8 and the optical sampling pulses P4, and outputting optical pulses P9;
a non-linear optical crystal element (116) for generating sum-frequency optical pulses of the optical pulses P4 and P8, a phase of the optical sampling pulses P4 and a phase of the optical pulses P8 being matched in the optical pulses P9;
a receptor (118) consisting of photo-electric converting elements, converting the sum-frequency optical pulses into detection signals (PS);
an A/D converter (119) for converting a peak voltage of the detection signals (PS) into digits;
and
a computer (120) for calculating the digits, generating eye-patterns, displaying images of the eye-patterns in a display section, and evaluating a waveform of the optical pulses P7, wherein n is an integer, and Δf is a frequency range.

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Dependencies are inferred from the claim text.

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Abstract

An optical sampling waveform measuring apparatus comprising:

a first electrical signal generator (SG1) for generating electric signals having a cycle frequency fsig;
a mode-locked fiber ring laser (110) which is pumped by the electric pulses P1, the mode-locked fiber ring laser (110) generating optical pulses P6 synchronous with clock signals of the electric pulses P1;
a pattern generator (111) for outputting a predetermined pattern of data signal rows, each of the data signal rows consisting of at least “0” (zero) and “1” (one), the data signal rows being synchronous with the clock signals of the electric pulses P1;
an optical intensity modulator (112) for modulating the optical pulses P6 based on the predetermined pattern, and outputting optical pulses P7;
an optical amplifier (113) for amplifying the optical pulses P7;
a polarization controller (114) for controlling a polarization direction of the optical pulses P7, and outputting optical pulses P8 having the cycle frequency fsig;
a second electrical signal generator (SG2) for generating electric sampling pulses P2 having the cycle frequency (fsig/n−Δf) synchronous with the electric pulses P1;
a passive mode-locked fiber ring laser (1) for emitting optical sampling pulses P10 having the cycle frequency (fsig/n−Δf) which corresponds to the electric sampling pulses P2;
a polarization direction controller (109) for controlling a polarization direction of the optical sampling pulses P10, and outputting optical sampling pulses P4 having the cycle frequency fsig;
a polarization beam splitter (115) for mixing the optical pulses P8 and the optical sampling pulses P4, and outputting optical pulses P9;
a non-linear optical crystal element (116) for generating sum-frequency optical pulses of the optical pulses P4 and P8, a phase of the optical sampling pulses P4 and a phase of the optical pulses P8 being matched in the optical pulses P9;
a receptor (118) consisting of photo-electric converting elements, converting the sum-frequency optical pulses into detection signals (PS);
an A/D converter (119) for converting a peak voltage of the detection signals (PS) into digits;
and
a computer (120) for calculating the digits, generating eye-patterns, displaying images of the eye-patterns in a display section, and evaluating a waveform of the optical pulses P7, wherein n is an integer, and Δf is a frequency range.

12 more elements