Electronics and Telecommunications Research Institute

Agency for Defense Development

Yongwoo Park

Hojun Ryu

Dong Woo Suh

Yeungjoon Sohn

Mun Cheol Paek

Hyeon-Bong Pyo

Hyeon Bong Pyo

Mun-Cheol Paek

Kilsoo Jeong

Jungsup Kim

Donghyeok Lee

Kyoungje Park

Juhang Sohn

Jaehyun Park

A band antenna EMP filter apparatus having HEMP protection capability is disclosed. The apparatus includes a discharging part, a band pass filtering part, and a residual current eliminating part. The discharging part primarily discharges a transient voltage due to a high altitude electromagnetic pulse (HEMP) when the HEMP is inputted through an input part receiving a radio frequency (RF) signal of an antenna. The band pass filtering part secondarily blocks a residual current primarily discharged by the discharging part and passes only a signal of a preset frequency band to output it through an output part. The residual current eliminating part limits a transient voltage of the HEMP by eliminating a residual current passing through the band pass filtering part.

Band antenna EMP filter apparatus having hemp protection capability

A leaky plasmon mode directional coupler and a polarization detection module for a magneto-optical pickup head, which uses the leaky plasmon mode directional coupler, are provided. The leaky plasmon mode directional coupler is manufactured by integrating a planar waveguide and a leaky plasmon mode waveguide, which share a cladding layer with each other, into one body. The polarization detection module includes the leaky plasmon mode directional coupler, a first photo diode, which is formed on the leaky plasmon mode directional coupler, and a second photo diode, which is located at an output port of the planar waveguide.

Leaky surface-plasmon mode directional coupler and polarization detection module for magneto-optical pickup head using the same

Provided is a focusing waveguide grating coupler using a leaky mode which can form single output beam while relieving the dependency on manufacturing processes. The focusing waveguide grating coupler of the present research includes: a substrate having a first refraction index n1; a first core layer having a second refraction index n2, the first core layer being formed on the substrate; a second core layer having a third refraction index n3, the second core layer being formed on the first core layer apart from the first core layer with a space d in between; a first cladding layer having a fourth refraction index n4, the first cladding layer being formed on the second core layer; a second cladding layer having a fifth refraction index n5, the second cladding layer being formed on the first cladding layer and inserted between the first core layer and the second core layer; and a Fresnel lens positioned on the second cladding layer, wherein the refractive indexes satisfy conditions of n5&#x3e;(n2, n3)&#x3e;n1 and n5&#x3e;n4; and light inputted through the first and second core layers to the Fresnel lens as radiated leaky beam by a leaky mode formed according to the conditions, and the leaky beam forms an optical focus by performing single directional coupling.

Highly efficient focusing waveguide grating coupler using leaky mode

Growing community of inventors

Daejeon, South Korea

Yongwoo Park