• Current Optics and Photonics
• /
• v.2 no.3
• /
• pp.241-249
• /
• 2018

We report a midinfrared dual-field-of-view (FOV) optical system design for an airborne electro-optical targeting system. To achieve miniaturization and weight reduction of the system, it has a common aperture and fore-optics for three different spectral wavelength bands: an electro-optic (EO) band ($0.6{\sim}0.9{\mu}m$), a midinfrared (IR) band ($3.6{\sim}4.9{\mu}m$), and a designation laser wavelength ($1.064{\mu}m$). It is free to steer the line of sight by rotating the pitch and roll axes. Our design co-aligns the roll axis, and the line of sight therefore has a fixed entrance pupil position for all optical paths, unlike previously reported dual-FOV designs, which dispenses with image coregistration that is otherwise required. The fore-optics is essentially an achromatized, collimated beam reducer for all bands. Following the fore-optics, the bands are split into the dual-FOV IR path and the EO/laser path by a beam splitter. The subsequent dual-FOV IR path design consists of a zoom lens group and a relay lens group. The IR path with the fore-optics provides two stepwise FOVs ($1.50^{\circ}{\times}1.20^{\circ}$ to $5.40^{\circ}{\times}4.32^{\circ}$), due to the insertion of two Si lenses into the zoom lens group. The IR optical system is designed in such a way that the location and f-number (f/5.3) of the cold stop internally provided by the IR detector are maintained when changing the zoom. The design also satisfies several important performance requirements, including an on-axis modulation transfer function (MTF) that exceeds 10% at the Nyquist frequency of the IR detector pitch, with distortion of less than 2%.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1147-1150
• /
• 2004

We studied on an electro-optical (EO) hysteresis, coming from the in-plane modulation of the molecular reorientation, in highly twisted nematic liquid crystal devices. Varying a ratio d/$P_0$ of the cell thickness d to the natural pitch $P_0$, the EO hysteresis and the twisted angle transition were observed and analyzed in terms of the periodicity of the in-plane modulation within the continuum theory.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.543-546
• /
• 2003

We studied the dielectric layer effect on the electro-optical (EO) properties of liquid crystal (LC) devices together with numerical simulations. Recently, it has been reported that the surface dielectric layer affects significantly the EO performances of LC microlens arrays and wide-viewing LC displays. it is found that the operation voltage of the LC device decreases with increasing the dielectric constant or with decreasing the thickness of the dielectric polymer layer. The experimental data agree well with theoretical results predicted in a simple dielectric model within the continuum formalism.

• Proceedings of the KSRS Conference
• /
• 2008.10a
• /
• pp.232-235
• /
• 2008

The mission of the EO(electro-optical) based low earth orbit satellite is provision of the high-resolution images required for GIS(Geographical Information Systems) establishment and the applications for environmental, agriculture and ocean monitoring. AEISS(Advanced Earth Imaging Sensor System) which is the main payload on the satellite consists of EOS(electro-optical subsystem) and PDTS(Payload Data Transmission Sub-system). IDHU(Image Data Handling Unit) which is one of the major unit in PDTS is capable of compression, storage, encryption and encoding. In this paper, the payload system of the EO based satellite is briefly introduced and the influence of the compression on AEISS is analyzed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.3
• /
• pp.219-223
• /
• 2003

The electro-optical (EO) performances of a multidomain verticial-alignment (MYA) cell on a homeotropic photopolymer have been investigated. In the absence of an electric field, the WVA cell achieved black state as LC alignment is homeotropic An electric field created by interdigitated electrodes and rib made after photolithograph using the photopolymer on both substrates causes a director deformation of a multidomain type. Good voltage transmittance curves for a MVA cell on the homeotropic photopolymer were observed. Also, the stable response time of MYA cell on the homeotropic photopolymer can be achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.11a
• /
• pp.477-480
• /
• 2003

We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. However, the transmittance of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film decreased greatly as cell gap decreases.

• ETRI Journal
• /
• v.24 no.4
• /
• pp.259-269
• /
• 2002

Polymers are emerging as new alternative materials for optical communication devices. We developed two types of polymer-based devices for optical communications. One type is for ultra high-speed signal processing that uses nonlinear optical (NLO) polymers in such devices as electro-optic (EO) Mach-Z${\ddot{e}} $ hnder (MZ) modulators and EO 2${\times}$2 switches. The other is for WDM optical communications that use low-loss optical polymers in such devices as 1${\times}$2, 2${\times}$2, 4-arrayed 2${\times}$2 digital optical switches (DOSs) and 16${\times}$16 arrayed waveguide grating (AWG) routers. For these devices, we synthesized a polyetherimide-disperse red 1 (PEI-DR1) side chain NLO polymer and a low-loss optical polymer known as fluorinated polyaryleneethers (FPAE). This paper presents the details of our development of these polymeric photonic devices considering all aspects from materials to packaging.

• Korean Journal of Remote Sensing
• /
• v.28 no.6
• /
• pp.671-682
• /
• 2012

Strong backscattering features from high-resolution Synthetic Aperture Rader (SAR) image provide useful information to analyze earth surface characteristics such as man-made objects in urban areas. The SAR image has, however, some limitations on description of detail information in urban areas compared to optical images. In this paper, we propose a new classification method using a fused SAR and Electro-Optical (EO) image, which provides more informative classification result than that of a single-sensor SAR image classification. The experimental results showed that the proposed method achieved successful results in combination of the SAR image classification and EO image characteristics.

• Proceedings of the Optical Society of Korea Conference
• /
• 2009.02a
• /
• pp.313-314
• /
• 2009

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07b
• /
• pp.1043-1046
• /
• 2003

We investigated the EO performances of the UV aligned twisted nematic liquid crystal display (TN-LCD) with the UV exposure on a-C:H thin film surface. LC alignment using UV exposure on the a-C:H thin film surface was achieved. Monodomain alignment of the UV aligned TN-LCD can be observed. An good EO characteristics of the UV aligned TN-LCD was observed with oblique ion beam exposure on the a-C:H thin film surface. Therefore, the EO property of the UV-aligned TN-LCD with UV exposure on the a-C:H thin film surface is almost the same as that of the rubbing-aligned TN-LCD on a polyimide (PI) surface.