Hyun Seo Kang

A Novel Low-Cost Fiber In-Line-Type Bidirectional Optical Subassembly

A novel low-cost fiber in-line-type bidirectional optical subassembly using a tilted fiber Bragg grating has been developed for fiber-to-the-home applications. We successfully realized a low-cost subassembly by reducing the number of components and simplifying the packaging process. The extinction ratio of 14.8 dB, receiver minimum sensitivity of -26.5 dBm at a bit-error rate of 10-12 and frequency response of 2.7 GHz were experimentally obtained. The electrical crosstalk between transmitter and receiver part was less than -86 dB up to 2.5 GHz.

Low-cost 1×2 plastic optical beam splitter using a V-type angle polymer waveguide for the automotive network

The design, fabrication, and characteristic of the plastic optical fiber (POF), beam splitter, for the automotive network, has been demonstrated. The fabricated 1×2 POF beam splitter consisted of a poly(methylmethacrylate) (PMMA) core, which had a structure of circular waveguide and a diameter of 0.98 mm, UV curable epoxy (PC-414) clading of 0.02 mm thickness, and three POF pigtails with multimedia oriented system transport standard ferrules. A 1×2 PMMA waveguide, which was designed to have an optimal angle of 15.8 deg at the beam splitting point, was fabricated using the injection molding method for mass production. The total volume of the fabricated 1×2 POF beam splitter is 48×18×12 mm3 with 1.2 m length input and output POF pigtails. From the measurement results, we experimentally confirm that the fabricated 1×2 POF beam splitter has excellent properties such as a beam splitting ratio of 50:50 ± 10 % and excess loss of less than 3.52 dB and it works well up to 250 Mbps for the automotive network.

Prediction of TEC power consumption for cooled laser diode module

In this study, the power consumption of TEC (thermoelectric cooler) is predicted using 3-D thermal FEM simulation and compared with experimental result. In addition to that, the effect of TEC configuration defined with the dimension and the number of pellets is discussed using commercialized product (RMT 1ML06-035-09AN) and its database to investigate the size effect. Results show that the cooling capacity of the TEC increases with increasing TEC pellet number. The power consumption of the module which the LD chip operates at 40 /spl deg/C dramatically decreases with power consumption equal to 1/3 of the laser diode module operating at 25 /spl deg/C.

MIRAGE: A Touch Screen based Mixed Reality Interface for Space Planning Applications

Space planning is one of the popular applications of VR technology including interior design, architecture design, and factory layout. In order to provide easier and efficient methods to accommodate physical objects into virtual space under plan, we suggest applying mixed reality (MR) interface. Our MR system consists of a video see-through display with a touch screen interface, mounted on a mobile platform, and we use screen space 3D manipulations to arrange virtual objects within the MR scene. Investigating the interface with our prototype implementation, we are convinced that our system will help users to design spaces in more easy and effective way.

Awareness system for bowel motility estimation based on artificial neural network of bowel sounds

Awareness system of bowel motility estimation based on an artificial neural network (ANN) model of bowel sounds obtained by an auscultation was devised. Twelve healthy males and 6 patients with delayed bowel motility were examined. BS signals generated during the digestive process were recorded from 3 colonic segments (ascending, descending and sigmoid colon), and then, the acoustical features (jitter and shimmer) of the individual BS segment were obtained. Only 6 features (J1,3, J3,3, S1,2, S2,1, S2,2, S3,2) highly correlated to the conventional colon transit time (CTT) were used as the features. Through k-fold cross validation, the correlation coefficient and mean average error between the CTTs and the values estimated by our algorithm were 0.89 and 10.6 hours, respectively. The devised system showed good potential for the continuous monitoring and estimating the bowel motility, instead of conventional radiography, and thus, it could be used as an awareness tool for the non-invasive measurement of bowel motility.

Xphere: A PC Cluster based Hemispherical Display System

Visual information has the greatest effect among five senses of human. Therefore, the satisfaction of visual information for representing virtual environments is necessary for good results in information acquisition, virtual training, virtual prototyping, etc. Recently, although there have been a large variety of display systems, there is no such a fully immersive and clearly projected display with high-resolution. In this paper, we describe a hemispherical display which supports a fully immersive experience and high-resolution images. In our display system for generating high-resolution images, a virtual scene image is divided into several pieces those are rendered by a PC cluster and projected with multiple projectors. In this paper, we also describe the PC cluster and projectors designed for optimized performance and a convenient control.

Experimental and theoretical characterization of optical signal out-coupling through V-grooved optical fiber cladding

We demonstrate a highly efficient in-fiber out-coupling device. The core mode is coupled to the cladding by a tilted fiber Bragg grating and then the cladding mode is out-coupled from the optical fiber through V-grooved cladding. The light emitting characteristics are investigated experimentally and a maximum out-coupling efficiency of 54.8% is obtained.

Self-amplified passive optical network using 8B10B line coding properties in Gigabit-Ethernet protocol

A cost-effective self-amplified network in a Gigabit-Ethernet passive optical network is demonstrated using 8B10B line coding properties. We explain the operational principles and experimental results including transmitter and receiver margin for an upstream channel.

1/10 Gb/s single transistor-outline-CAN bidirectional optical subassembly for a passive optical network

Abstract. We propose a novel, low-cost bidirectional optical subassembly (BOSA) that uses a single glass-sealed conventional transistor-outline (TO)-CAN package for passive optical network application. In this BOSA, optical transmitting and receiving functions are incorporated into a silicon optical bench and in a TO-CAN package, respectively. With these features, the optical and electrical crosstalk is efficiently suppressed. The single TO-CAN BOSA has an extinction ratio of 11.69 dB and output power of 2.93 dBm for 1.25  Gb/s operation. The penalty of optical dispersion is 1.2 dB after 20-km single-mode fiber transmission. The receiver sensitivity is less than −30  dBm at a bit error rate of 10−3 for 10.3  Gb/s operation and the signal crosstalk penalty of a single TO-CAN BOSA is 0.8 dB.

Compact bidirectional optical subassembly vertically stacked with 1.25-Gbps transmitter and 10-Gbps receiver for passive optical networks

A compact bidirectional optical subassembly (BOSA) for a 1.25/10-Gbps passive optical network is developed. A vertically stacked 1.25-Gbps transmitter based on a silicon optical bench, and a 10-Gbps receiver based on a low temperature cofired ceramic are implemented to realize low-cost manufacturing and miniaturization for single package application. The proposed BOSA delivers an extinction ratio more than 10 dB at 1.25-Gbps modulation, optical output coupling efficiency is more than 60%, rise and fall time is under 300 ps, and the side mode suppression ratio is more than 35 dB for the transmitter part. For the receiver part, responsivity is more than 0.6 A/W, and sensitivity is lower than -17 dBm at a 10-Gbps bit error rate 10-12 and -21 dBm at BER 10-3 without forward error correction. The cross talk between receiver and transmitter is less than -53 dB up to 10 GHz, and optical isolation is 33 dB.