US 11,902,495 B2 · Ultrafast camera system and measurement method thereof

Abstract

An ultrafast camera system includes a sensor head that injects an optical pulse train input from a pulsed laser onto a surface of a measurement target and outputs an optical signal reflected from the surface, and a timing detector that receives the optical signal whose time-of-flight is changed after passing through the sensor head and outputs an electrical signal corresponding to a timing error between the optical signal and a reference signal. Another ultrafast camera system includes a wavelength dispersion device to disperse an optical pulse train of a pulsed laser into a wavelength spectrum, a lens that vertically injects continuous wavelength signals dispersed into the wavelength spectrum onto a measurement line, and a timing detector that receives an optical signal including the continuous wavelength signals reflected from the measurement line, and outputs a timing error between the reference signal and the continuous wavelength signals as a signal intensity.

Claims18

Dependent claims

An ultrafast camera system comprising:

a sensor head that injects an optical pulse train input from a pulsed laser onto a surface of a measurement target and outputs an optical signal reflected from the surface;
and
a timing detector that receives the optical signal whose time-of-flight is changed after passing through the sensor head and outputs an electrical signal corresponding to a timing error between the optical signal and a reference signal,
wherein the timing detector modulates the optical signal using the reference signal in a loop where the optical signal is divided and then the divided signals circulate in different directions, and obtains an intensity difference of two interference signals which are generated from interference between the signals circulating the loop, through balanced photodetection, and
wherein the intensity difference of the two interference signals is an electrical signal proportional to a timing error between the optical signal and the reference signal.

2 more elements

An ultrafast camera system comprising:

a wavelength division multiplexer that generates sub-pulses by wavelength-dividing an optical pulse train output from a pulsed laser;
a wavelength dispersion device to disperse the sub-pulses generated by the wavelength division multiplexer into different angles according to each wavelength of the sub-pulses;
a lens that vertically injects the sub-pulses dispersed at an angle corresponding to wavelength by the wavelength dispersion device onto a measurement target;
a timing detector that receives an optical signal obtained by multiplexing the sub-pulses reflected from points of the measurement target and outputs electrical signals corresponding to timing errors between a reference signal and sub-pulses included in the optical signal by using a plurality of balanced photodetectors;
and
a reference signal source to output the reference signal synchronized with the pulsed laser,
wherein the sub-pulses reflected from the points on the measurement target are entered to the timing detector via the lens, the wavelength dispersion device, and the wavelength division multiplexer, and
wherein the reference signal source comprises
an electrical pulse generator that generates photocurrent pulses as the reference signal by performing photoelectric transformation on the optical pulse train of the pulsed laser, or
a voltage-controlled oscillator that generates a microwave signal as the reference signal, which is frequency-locked by the optical pulse train of the pulsed laser.

7 more elements

An ultrafast camera system comprising:

a wavelength dispersion device to disperse an optical pulse train of a pulsed laser into a wavelength spectrum;
a lens that vertically injects continuous wavelength signal dispersed into the wavelength spectrum onto a measurement line;
a timing detector that receives an optical signal including the continuous wavelength signal reflected from the measurement line, and outputs a signal intensity in the wavelength spectrum, which is corresponding to a timing error between a reference signal and the continuous wavelength signal;
and
a reference signal source to output the reference signal synchronized with the pulsed laser,
wherein the optical signal including the reflected continuous wavelength signal is entered to the timing detector via the lens and the wavelength dispersion device, and
wherein the reference signal source comprises
an electrical pulse generator that generates photocurrent pulses as the reference signal by performing photoelectric transformation on the optical pulse train of the pulsed laser, or
a voltage-controlled oscillator that generates a microwave signal as the reference signal, which is frequency-locked by the optical pulse train of the pulsed laser.

6 more elements

Dependencies are inferred from the claim text.

Ultrafast camera system and measurement method thereof

Life of this patent

Ultrafast camera system and measurement method thereof

Life of this patent

Abstract

Claims18