Korea Advanced Institute of Science and Technology

Osong Medical Innovation Foundation, Korea University Research and Business Foundation

Jungwon Kim

Yongjin Na

Dohyeon Kwon

Chan-Gi Jeon

Kyoungsik Yu

Hayun Cecillia Chung

Youngjae Jeong

Hyunsoo Kwak

Changmin Ahn

Minji Hyun

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.

Ultrafast camera system and measurement method thereof

A sensing system is provided. The sensing system includes an electrical pulse generator that receives first optical pulses output from a pulsed laser, through a first path, and photo-electrically converts the first optical pulses to generate an electrical pulses; and an optical phase detector that receives second optical pulses output from the pulsed laser, through a second path, and outputs an electrical signal that corresponds to a phase error between the electrical pulses and the second optical pulses based on electro-optic sampling.

Optical phase detector using electrical pulse that corresponds to a phase error between electrical pulses and optical pulses, and sensing system including the same

A multi-channel sensing system is disclosed. The multi-channel sensing system includes a multi-channel sensor connector that wavelength-divides an optical pulse output from a pulsed laser into a plurality of channels in a spectrum domain, transmits each of a plurality of optical sub-pulses generated from the wavelength division to a channel path allocated for each channel in multi-channel paths, multiplexes the plurality of optical sub-pulses passed through the multi-channel paths and outputs an optical signal including the multiplexed optical sub-pulses; and a multi-channel optical phase detector that receives the optical signal output from the multi-channel connector and a reference signal which is synchronized to the pulse laser, and detects a channel-specific electrical signal that corresponds to a timing error between each of the plurality of optical sub-pulses included in the optical signal and the reference signal. At lease one of sensors is connected to at least one of the multi-channel paths.

Multi-channel optical phase detector, multi-channel sensing system and multi-laser synchronization system

A frequency stabilizer includes: a delay line interferometer that receives an optical signal corresponding to one frequency mode of a pulsed laser, divides and transmits the received optical signal to a reference arm and a delay arm including an optical fiber delay line, and then outputs an interference signal between signals passing through the reference arm and the delay arm; a photoelectric converter that converts the interference signal into an electrical signal; a mixer that generates a baseband signal of the electrical signal by mixing a carrier frequency signal; and a feedback controller that transmits a control signal generated based on the baseband signal to the pulsed laser. The optical signal passing through the delay arm is weighted with a delay time caused by the optical fiber delay line compared to the optical signal passing through the reference arm, and the optical signal passing through the delay arm is frequency shifted to a carrier frequency of an oscillator. A carrier-envelope offset frequency of the pulsed laser is stabilized by an offset frequency stabilizer.

Optical frequency stabilizer using optical fiber delay line, and method for generating stable optical frequency signal

The present disclosure relates to an integrated phase detector. In an embodiment, a first multi-mode interference coupler that receives the optical signal and outputs optical signals with a plurality of modes, and a second multi-mode interference coupler that receives one of the optical signals with the plurality of modes and a modulated signal generated through performing a phase modulation on another of the optical signals with the plurality of modes by the microwave signal, and outputs a first optical interference signal and a second optical interference signal may be included.

Integrated optical-microwave phase detecting apparatus and method based on 3X3 MMI coupler

A low-jitter digital clock signal generating system which uses optical pulses output from a pulse laser includes a first balanced photodetector that converts first and second optical pulses with a delayed time interval into first and second electrical pulses through first and second photodiodes and outputs first and second modulated pulses generated by allowing the first and second electrical pulses to partially overlap each other, a second balanced photodetector that converts third and fourth optical pulses with the delayed time interval into third and fourth electrical pulses through third and fourth photodiodes, and outputs a second modulated pulse generated by allowing the third and fourth electrical pulses to partially overlap each other, and a capacitor. The capacitor is charged by the first modulated pulse, is discharged by the second modulated pulse, and outputs a voltage according to the charging and discharging as a clock signal.

Growing community of inventors

Daejeon, South Korea

Jungwon Kim