Dong Hoon Sim

Transmission of 10-Gb/s and 40-Gb/s Signals over 3.7 km of Multimode Fiber using Mode-Field Matched Center Launching Technique

We experimentally demonstrate the transmission of 10-Gb/s and 40-Gb/s signals over 3.7 km of multimode fiber by using the mode-field matched center launching technique.

Robustness Evaluation of MMF Transmission Link using Mode-Field Matched Center-Launching Technique

We evaluate the robustness of the MMF transmission link implemented by using the mode-field matched center-launching technique against the mechanical perturbations such as the lateral offset between the fiber connectors, fiber bending, and fiber shaking.

Crosstalk analysis in homogeneous multi-core two-mode fiber under bent condition.

We analyze the inter-core crosstalk in homogeneous multi-core two-mode fibers (MC-TMFs) under bent condition by using the coupled-mode equations. In particular, we investigate the effects of the intra-core mode coupling on the inter-core crosstalk for two different types of MC-TMFs at various bending radii. The results show that the inter-core homo-mode crosstalk of LP(11) mode is dominant under the gentle fiber bending condition due to its large effective area. However, as the fiber bending becomes tight, the intra-core mode coupling is significantly enhanced and consequently makes all the inter-core crosstalk levels comparable to each other regardless of the mode. A similar tendency is observed at a reduced bending radius when the difference in the propagation constants between modes is large and core pitch is small.

Direct-Detection Receiver for Polarization-Division-Multiplexed OOK Signals

We propose a direct-detection receiver capable of detecting polarization-division-multiplexed (PDM) ON-OFF keying (OOK) signals without using a dynamic polarization controller. The proposed receiver, consisted of a polarization-beam splitter, three 1 × 2 directional couplers, three photodetectors, three analog-to-digital converters, and a digital signal processing unit, can discriminate among the four symbol combinations of the PDM-OOK signal with the help of a short training sequence. For a demonstration, we show that the proposed receiver can detect a 20-Gb/s PDM-OOK signal even when its polarization is scrambled at the speed of 3 Mrad/s.

Analysis of inter-core crosstalk in homogeneous multi-core two-mode fiber under bent condition

We analyze the inter-core crosstalk in a homogeneous multi-core two-mode fiber under bent condition by using coupled-mode equations. The effects of the intra-core mode coupling on the inter-core crosstalk are investigated for various bending radii.

High-speed MMF transmission by using mode-field matched center-launching technique

We have demonstrated the transmission of 160-Gb/s signal (16 × 10 Gb/s) over 12.2 km of multi-mode fiber by using the mode-field matched center-launching technique. The performance of this technique is robust against the mechanical perturbations such as the lateral offset between fiber connectors, fiber bending, and fiber shaking.

A simple and accurate measurement method of chromatic dispersion of multi-mode fiber

We demonstrate that the chromatic dispersion of multi-mode fiber can be measured with excellent accuracy by using the modulation-phase-shift method together with the mode-field matched center-launching technique.

Design method for bidirectionally pumped distributed Raman amplifier

We develop an efficient design method for the bi-directionally pumped distributed Raman amplifier (DRA). Using this method, we have designed a bi-directionally pumped DRA having a small gain ripple (< 1.1 dB) over the bandwidth of 90 nm.