OPTICS 2018 Abstracts


Full Papers
Paper Nr: 4
Title:

Generation of High Stability Microwave Signal using Optoelectronic Oscillator based on Long Fibre Delay Line

Authors:

Mohamed Mousa, Abdelrahman E. Afifi, Mohamed Abouelatta and Kamel M. Hassan

Abstract: An optoelectronic oscillator based on long fibre delay line to generate high stable microwave signal has been investigated and implemented experimentally. Mathematical model for this oscillator has been proposed. The experimental results are taken for different delay line lengths (2.1 Km, 4.2 Km and 6.6 Km respectively). The generated signal has a narrow bandwidth (less than 200 Hz) at carrier frequency 2.31 GHz and its phase noise is less than -80 dBc/Hz at 1 KHz offset. Comparison of the experimental results and analytical ones has been done. A critical length (Lc) concept of the used fibre delay line has been introduced as a design parameter for the proposed optoelectronic oscillator.

Paper Nr: 5
Title:

Physical Layer Impairments in Cascaded Multi-degree CDC ROADMs with NRZ and Nyquist Pulse Shaped Signals

Authors:

Diogo G. Sequeira, Luís G. Cancela and João L. Rebola

Abstract: Nowadays, reconfigurable optical add/drop multiplexers (ROADMs) are mainly based on broadcast and select (B&S) and route and select (R&S) architectures. Moreover, the most used components to implement the colorless, directionless and contentionless (CDC) ROADM add/drop structures are the multicast switches (MCSs) and the wavelength selective switches (WSSs). In-band crosstalk, amplified spontaneous emission (ASE) noise accumulation and optical filtering are physical layer impairments (PLIs) that become more enhanced in a CDC ROADM cascade. In this work, we investigate the impact of these PLIs in a cascade of CDC ROADMs based on both B&S and R&S architectures, with MCSs and WSSs-based add/drop structures and for nonreturn-to-zero (NRZ) rectangular and Nyquist pulse shaped signals. We show that the optical filtering impairment is more limiting for a R&S architecture. We also show that the ASE noise accumulation after 32 cascaded ROADMs leads to a 10 dB optical signal-to-noise ratio (OSNR) penalty for all ROADM degrees investigated. We have also concluded that the in-band crosstalk leads to a 1 dB OSNR penalty, after 13 and 24 cascaded 16-degree CDC ROADMs based on B&S for, respectively, NRZ rectangular and Nyquist pulse shapes. For a R&S architecture, the in-band crosstalk is not so harmful.

Short Papers
Paper Nr: 3
Title:

Adaptive Channel Allocation Algorithm Suitable for WDM Networks: An Analytical Study

Authors:

Peristera A. Baziana

Abstract: In this paper, we adopt a network configuration and an efficient synchronous transmission access protocol suitable for WDM networks of passive star topology. Especially, a single control channel is assumed for the control information exchange, prior to the data packets transmission, in order to properly coordinate the data packets communication. According to the proposed WDMA scheme, a data channel is assigned at each station that attempts data packet transmission, totally avoiding the collisions over the data multi-channel system. The system performance measures are analytically derived based on a Markovian model. Numerical results are studied for diverse numbers of data channels.

Paper Nr: 6
Title:

Multi-wavelength Erbium-doped Fiber Laser with Tunable Wavelength Spacing

Authors:

Xing Luo, Tong Hoang Tuan, Than Singh Saini, Hoa Phuoc Trung Nguyen, Takenobu Suzuki and Yasutake Ohishi

Abstract: We demonstrate a stable multi-wavelength ring cavity erbium-doped fiber laser in this paper. A fiber Michelson interferometer is inserted into the ring laser cavity acting as a multi-wavelength filter to realize multi-wavelength operation. The optical path difference of the two arms of the fiber Michelson interferometer is tunable by changing the optical delay line. Thus, the wavelength spacing of the multi-wavelength laser is tunable by tuning the optical delay line in the Michelson interferometer. Eventually, the tunable range of the wavelength spacing is realized from 0.045 nm to 0.7 nm in our experiments. More than 60 wavelengths within 3 dB flatness with wavelength spacing of 0.0474 nm can be achieved.

Paper Nr: 7
Title:

Fabrication of a Novel Tellurite Hollow Core Optical Fiber and Supercontinuum Light Propagation in Its Hollow Core

Authors:

Tong Hoang Tuan, Nobuhiko Nishiharaguchi, Takenobu Suzuki and Yasutake Ohishi

Abstract: For the first time, we experimentally demonstrated the fabrication of a tellurite HC-PCF which has a large hexagonal hollow core in the center. The tellurite glass was developed by our group based on TeO2, ZnO, Li2O and Bi2O3 oxides. The fiber was successfully obtained by using rotational casting and rod in tube methods. A supercontinuum light source from 500 nm to more than 1500 nm was launched into the hollow core of the fiber. The result shows that the light beam can be coupled and propagated in the hollow core by the fundamental mode.