Korea Advanced Institute of Science and Technology

Neuros Co., Ltd.

Korea Research Institute of Standards and Science

Seung-Woo Kim

Young-Jin Kim

Myung-Hwan Kim

Byung Jae Chun

Jong-Seon Kim

Hyun Jay Kang

Sung Soo Jung

Seung-Chul Kim

In-Yong Park

Min-Seok Kim

Heesuk Jang

Ii-Hyung Jang

Jung-Jae Park

Il-Hyung Jang

Jong-Han Jin

Yong Bong Lee

Provided are a device and method for free space coherent optical communications by means of an automatic compensation for phase noise in atmosphere using a femtosecond laser optical comb, and more particularly, a device and method for free space coherent optical communications by means of an automatic compensation for phase noise in atmosphere using a femtosecond laser optical comb, in which a phase shift value due to atmospheric turbulence is obtained from reflected light of transmission light generated from a femtosecond laser optical comb and the transmission light is pre-distorted on the basis of the phase shift value, thereby pre-compensating, in a transmission end, for phase noise due to atmospheric turbulence.

Device and method for free space coherent optical communication by means of automatic compensation for phase noise in atmosphere using femtosecond laser optical comb

The present invention relates to a device and a method for performing overall frequency stabilization of a femtosecond laser optical comb by using optical modes directly extracted from the optical comb, and more particularly, to a device and a method for performing overall frequency stabilization of a femtosecond laser optical comb by using optical modes directly extracted from the optical comb capable of stabilizing an overall range of frequencies of the femtosecond laser optical comb by using optical modes directly extracted from the optical comb and generating a cw laser and pulse having an excellent frequency stability and linewidth from the stabilized optical comb.

Device and method for performing overall frequency stabilization of femtosecond laser optical comb by using optical modes directly extracted from optical comb

A method and apparatus for determining phase sensitivity of an accelerometer based on an analysis of the harmonic components of the interference signal, which can estimate phase lags of an accelerometer through an analysis of the interference signal obtained using a single photo-detector when the accelerometer moves in sinusoidal motion with an initial phase of vibration. The method comprises the steps of obtaining an interference signal in a time domain generated from a signal reflected by an accelerometer and a fixed mirror using a single photo-detector; transforming the interference signal in the time domain into a signal in a frequency domain including a plurality of harmonic signals by Fourier transform; and determining the phase sensitivity of the accelerometer using initial phase of vibration displacement of the accelerometer, which is included in the interference signal in the frequency domain.

Method and apparatus for determining phase sensitivity of an accelerometer based on an analysis of the harmonic components of the interference signal

The present invention relates to a vibration-insensitive interferometer using a high-speed camera and a continuous phase scanning method. The interferometer measures a measurement target by completely isolating influences of externally occurring vibrations from a frequency domain. The interferometer includes a light source unit for emitting light. A light transmission unit radiates the light emitted from the light source unit to the measurement target, splits light reflected from the measurement target into reference light and measurement light, and allows the reference light and the measurement light to interfere with each other, thus generating an interference fringe. A continuous phase scanning unit for radiates the reference light split by the light transmission unit through continuous phase scanning. A high-speed camera acquires an interference fringe generated by both the measurement light radiated through the light transmission unit and the reference light radiated through the continuous phase scanning unit.

Vibration-insensitive interferometer using high-speed camera and continuous phase scanning method

Disclosed herein is a laptop-size high-order harmonic generation apparatus using near field enhancement. The laptop-size high-order harmonic generation apparatus using near field enhancement includes a femtosecond laser generator, light transfer means for transferring light output from the femtosecond laser generator, micro patterns formed of metallic thin films and configured to have nano-sized apertures for generating near field enhancement when the light output from the light transfer means passes through the micro patterns, a gas supply unit for supplying inert gas to the light when the light transferred through the light transfer means passes through the micro patterns, and a vacuum chamber for accommodating the micro patterns and the gas supply unit under a vacuum atmosphere.

Laptop-size high-order harmonic generation apparatus using near field enhancement

In the method and a device for detecting the phase of a moving object using a heterodyne interferometer, a heterogeneous mode helium-neon laser is used as a direct light source to increase a measuring speed, a measuring resolution, and minimize the loss of the light source. Signals, which have only a frequency difference between reference signals or measured signals and arbitrary signals, are extracted from signals which are obtained by multiplying the arbitrary frequency signals by the reference or measured signals. After frequencies of the reference and measured signals are converted, a phase difference of the extracted signals and displacement of the moving object is measured. The system includes a laser light source, an optical interferometer, a frequency converter, and a phase measurer. The light source uses output light, emitted from the laser generator, which is stabilized in frequency, and has two frequencies which are at right angles to each other and linearly polarized.

Heterodyne laser interferometer using heterogenous mode helium-neon laser and super heterodyne phase measuring method

An ornithopter with an airframe structure that is lightweight, simple and stable and can generate sufficient lift and thrust. The ornithopter comprises a body, a main wing attached to an upper portion of a front section of the body, and a tail wing attached to a rear section of the body. The ornithopter further comprises a power source and a power transmission mechanism installed within a housing of the body. The main wing includes a wing frame composed of a plurality of frame rods and a skin attached to the wing frame for forming an outline of the main wing. The wing frame of the main wing is supported by a support means exposed to the outside at the upper portion of the front section of the body. The power transmission mechanism includes a gear train for adjusting the rotational motion of the power source at a proper speed and transferring it to the main wing, and connecting rods for converting the rotational motion into a swing motion of the main wing. Flight time of the ornithopter can be prolonged considering its weight and the power source can be easily manipulated.

Power-driven ornithopter

A power-driven ornithopter piloted by a remote controller wherein a takeoff and landing motion, a climbing and descending motion, and a turning motion of the ornithopter can be controlled using the remote controller. The ornithopter comprises a body, a main wing attached to an upper portion of a front section of the body, and tail wings attached to a rear section of the body. An electric motor, a power transmission mechanism, a battery, first and second servo motors and a controller are installed within a housing of the body. A crank arm is connected to a rotating shaft of the first servo motor and a connecting rod attached to a free end of the crank arm is then pivotally connected to a lower edge of the horizontal tail support. The second servo motor is mounted into a recess formed at an upper side of a rectangular parallelepiped of the horizontal tail support and a rotating shaft of the second servo motor is disposed on a central axis of the horizontal tail. A vertical tail support is supported by the rotating shaft of the second servo motor so that it can be swung on the rotating shaft of the second servo motor in a right and left direction as the rotating shaft of the second servo motor rotates.

Growing community of inventors

Daejeon, South Korea

Seung-Woo Kim