Search | Korea Science

Kim, Jun-Hyong;Yang, Hoe-Young;Yu, Chong-Hee;Lee, Hyun-Yong
- Transactions on Electrical and Electronic Materials
- /
- v.9 no.4
- /
- pp.163-168
- /
- 2008
Photonic crystal structures have been received considerable attention due to their high optical sensitivity. One of the techniques to construct their structure is the dip-pen lithography (DPN) process, which requires a nano-scale resolution and high reliability. In this paper, we propose a two dimensional photonic crystal array to improve the sensitivity of optical biosensor and DPN process to realize it. As a result of DPN patterning test, we have observed that the diffusion coefficient of the mercaptohexadecanoic acid (MHA) molecule ink in octanol is much larger than that in acetonitrile. In addition, we have designed and fabricated optical waveguides based on the mach-zehnder interferometer (MZI) for application to biosensors. The waveguides were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The MZI optical waveguides were measured of the optical characteristics for the application of biosensor.
https://doi.org/10.4313/TEEM.2008.9.4.163 인용 PDF KSCI

Park, Jae-Seok;Jeong, Myung-Yung;Kim, Chang-Seok
- Journal of the Optical Society of Korea
- /
- v.15 no.4
- /
- pp.380-385
- /
- 2011
Common-path interferometers are widely used for endoscopic optical coherence tomography (OCT) because an arbitrary arm length can be chosen for the endoscopic imaging probe. However, the scheme suffers from the limited range of the sample position distance from the end of the imaging probe because the position between the reference reflector and the sample is limited by the optical path-length difference (OPD) to induce an interference signal. In this study, we developed a novel method for compensating the arbitrary sample position in common-path swept-source OCT by adding an extra Mach-Zehnder interferometer in the post-path of the interfered optical signal. Theoretical analysis and an experimental demonstration of imaging depth tuning for the flexible sample position of an endoscopic OCT image are discussed. After post-tuning of sample position distance, the positioning limitation between the reference reflector and the sample can be solved for various sample positions over a range of 26 mm for the cross-sectional images of a fish eye sample.
https://doi.org/10.3807/JOSK.2011.15.4.380 인용 PDF KSCI

Zhou, Wensong;Li, Hui;Dong, Yongkang;Wang, Anbang
- Smart Structures and Systems
- /
- v.18 no.3
- /
- pp.471-484
- /
- 2016
Optical fiber sensors have been proven that they have the potential to detect high-frequency ultrasonic signals, in structural health monitoring field which generally refers to acoustic emission signals from active structural damages and guided waves excited by ultrasonic actuators and propagating in waveguide. In this work, the sensing properties of optical fiber sensors based on Mach-Zehnder interferometer were investigated in the metal plate. Analytical formulas were conducted first to explore the parameters affecting its sensing performances. Due to the simple and definable frequency component, the Lamb wave excited by the piezoelectric wafer was employed to study the sensitivity of the proposed optical fiber sensors with respect to the frequency, rather than the acoustic emission signals. In the experiments, according to above investigations, spiral shape optical fiber sensors with different size were selected to increase their sensitivity. Lamb waves were excited by a circular piezoelectric wafer, while another piezoelectric wafer was used to compare their voltage responses. Furthermore, by changing the excitation frequency, the tuning frequency characteristic of the proposed optical fiber sensor was also investigated experimentally.
https://doi.org/10.12989/sss.2016.18.3.471 인용 KSCI