Optica
-
Nature Photonics, a peer-reviewed scientific journal, released a paper written by a KAIST research team on the time-of-flight measurement.
Professor Seung-Woo Kim of the Mechanical Engineering Department, KAIST, and his research team published the result of their study on the measurement of 1 nanometer (nm) precision.
“The time-of-flight of light pulses has long been used as a direct measure of distance, but state-of-the-art measurement precision using conventional light pulses or microwaves peaks at only several hundreds of micrometers. Here, we improve the time-of-flight precision to the nanometer regime by timing femtosecond pulses through phase-locking control of the pulse repetition rate using the optical cross-correlation technique,” Professor Kim said.
According to the experiment conducted by the research team, “An Allan deviation of 117 nm in measuring a 700m distance in air at a sampling rate of 5 millisecond (ms) once the pulse repetition is phased-locked, which reduces to 7 nm as the averaging time increases to 1 second (s).”
When measuring an object located in a far distance, a laser beam is projected to the object, and the reflected light is analyzed; the light is then converted into an electric signal to calculate the distance. In so doing, Professor Kim said, the conventional method of measurement creates at least 1 mm of deviation.
He argues, “This enhanced capability is maintained at long range without periodic ambiguity, and is well suited to lidar applications. This method could also be applied to future space missions involving formation-flying satellites for synthetic aperture imaging and remote experiments related to general relativity theory."
Nature Photonics published the article online on August 8, 2010.
2010.08.18 View 10823 -
KAIST Research Team Unveils Method to Fabricate Photonic Janus Balls
A research team led by Prof. Seung-Man Yang of the Department of Chemical and Biomolecular Engineering has found a method to fabricate photonic Janus balls with isotropic structural colors.
The finding draws attention since the newly-fabricated photonic balls may prove useful pigments for the realization of e-paper or flexible electronic displays.
The breakthrough was published in the Nov. 3 edition of the science journal "Advanced Materials." The Nov. 6 issue of "Nature" also featured it as one of the research highlights under the title of "Future Pixels."
Prof. Yang"s research team found that tiny marbles, black on one side and colored on the other, can be made by "curing" suspensions of silica particles with an ultraviolet lamp. When an electric field is applied, the marbles line up so that the black sides all face upwards, which suggests they may prove useful pigments for flexible electronic displays.
The researchers suspended a flow of carbon-black particles mixed with silica and a transparent or colored silica flow in a resin that polymerizes under ultraviolet light. They then passed the mixture through a tiny see-through tube. The light solidified the silica and resin as balls with differently colored regions, each about 200 micrometers in diameter.
Over the last decades, the development of industrial platforms to artificially fabricate structural color pigments has been a pressing issue in the research areas of materials science and optics. Prof. Yang, who is also the director of the National Creative Research Initiative Center for Integrated Optofluidic Systems, has led the researches focused on fabrication of functional nano-materials through the process of assembling nano-building blocks into designed patterns.
The "complementary hybridization of optical and fluidic devices for integrated optofluidic systems" research was supported by a grant from the Creative Research Initiative Program of the Ministry of Education, Science & Technology.
2008.11.12 View 12984 -
Professor Yang Named Recipient of Dupont Science & Technology Award
Professor Yang Named Recipient of Dupont Science & Technology Award
- Named as the recipient of Dupont Science & Technology Award of 2007- In recognition of his development of optical?bio-functional photonic crystal structures through Self-assembly of nanoparticles
Seung-Man Yang, a professor of Chemical and Biomolecular Engineering of KAIST (President Nam Pyo Suh) and the president of the National Creative Research Initiatives Center for Photon and Fluid Integrated Circuit by the Ministry of Science and Technology, has been named as the recipient of Dupont Science & Technology Award.
Dupont Korea, associate of Dupont, a world-class science firm, has established and conferred ‘Dupont Science & Technology Award’ since 2002 to promote basic sciences and industrial development of Korea. Dupont Science & Technology Awards are awarded to scientists of universities or state-run institutes who have made outstanding R&D achievements in the fields of Chemistry, Chemical Engineering, Material Science and Material Engineering within five years. Dupont Korea announced on May 2, 2007 that Professor Yang is the recipient of the award this year, following the strict examination by the Koran Academy of Science and Technology (KAST).
The reason for the award is Professor Yang’s development of prototype optical?bio-functional photonic crystal structures that can process a huge amount of data, resulting from a study that has discovered the principle of Self-assembly where multifunctional nanoparticles are manufactured and assembled for themselves.
Professor Yang’s recent research result about photon structures and nano patterns was published by Nature (February 2, 2006 edition); posted on Heart-Cut, the portal site of the American Chemistry Society (ACS), as highlight paper two times (November 4, 2002 and May 1, 2006); and introduced at Research/Researcher of MRS Bulletin by the U.S. Material Research Society (MRS) as main paper in December 2003. Professor Yang is very famous in Korea and abroad for the excellences of his research achievements and has made request seminars at Harvard University, University of Wisconsin, Caltech, University of California, etc. He is also invited speaker and session organizer of the MRS and the SPIE.
2007.05.08 View 17094 -
H.Y.Choi won BSPA
H.Y.Choi won BSPA
Hyun-Young Choi, Doctor’s course at the Lightwave Systems Research Laboratory (LSRL) of Department of Electrical Engineering of KAIST (Professor in charge Yoonchul Jung), won the Best Student Paper Awards (BSPA) in the Asia-Pacific Optical Communications 2006.
BSPA is awarded to the most prospective paper in the field of Optical Transmission, Switching, and Subsystems. Choi suggested an OSNR monitoring technique among performance monitoring techniques for the efficient maintenance and management of optical network in her paper. Her technique is based on a polarization-nulling method using the polarization features of optical signals. It employs polarization mode dispersion compensator and acousto optic tunable filter (AOTF) to prevent monitoring errors arising from polarization mode dispersion (PMD) and non-linear double refraction, which considerably improves the monitoring technique and makes it possible to demonstrate a technique proposed at ultra long haul network.
2006.10.16 View 13268