Patent ID: 7068360

Claim:
An optical sampling waveform measuring apparatus comprising: a first electrical signal generator (SG 1 ) for generating electric signals having a cycle frequency f sig ; a mode-locked fiber ring laser ( 110 ) which is pumped by the electric pulses P 1 , the mode-locked fiber ring laser ( 110 ) generating optical pulses P 6 synchronous with clock signals of the electric pulses P 1 ; 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 P 1 ; an optical intensity modulator ( 112 ) for modulating the optical pulses P 6 based on the predetermined pattern, and outputting optical pulses P 7 ; an optical amplifier ( 113 ) for amplifying the optical pulses P 7 ; a polarization controller ( 114 ) for controlling a polarization direction of the optical pulses P 7 , and outputting optical pulses P 8 having the cycle frequency f sig ; a second electrical signal generator (SG 2 ) for generating electric sampling pulses P 2 having the cycle frequency (f sig /n−Δf) synchronous with the electric pulses P 1 ; a passive mode-locked fiber ring laser ( 1 ) for emitting optical sampling pulses P 10 having the cycle frequency (f sig /n−Δf) which corresponds to the electric sampling pulses P 2 ; a polarization direction controller ( 109 ) for controlling a polarization direction of the optical sampling pulses P 10 , and outputting optical sampling pulses P 4 having the cycle frequency f sig ; a polarization beam splitter ( 115 ) for mixing the optical pulses P 8 and the optical sampling pulses P 4 , and outputting optical pulses P 9 ; a non-linear optical crystal element ( 116 ) for generating sum-frequency optical pulses of the optical pulses P 4 and P 8 , a phase of the optical sampling pulses P 4 and a phase of the optical pulses P 8 being matched in the optical pulses P 9 ; 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 P 7 , wherein n is an integer, and Δf is a frequency range.