Attenuation in waveguides on FR-4 boards due to periodic substrate undulations

© 2007 Optical Society of America. The definitive version of this paper is available at: http://dx.doi.org/10.1364/AO.46.002234DOI: 10.1364/AO.46.002234The guided-mode attenuation associated with optical-interconnect-polymer waveguides fabricated on FR-4 printed-circuit boards is quantified. The rigorous transmission-line network approach is used and the FR-4 substrate is treated as a long-period substrate grating. A quantitative metric for an appropriate matrix truncation is presented. The peaks of attenuation are shown to occur near the Bragg conditions that characterize the leaky-wave stop bands. For a typical 400 µm period FR-4 substrate with an 8 µm corrugation depth, a buffer layer thickness of about 40 µm is found to be needed to make the attenuation negligibly small

A 60GHz Wireless Access Scheme with Electrical LO Devices Free in Mobile Terminals and Base Stations

Abstract: we propose a 60GHz wireless access network scheme with centralized LO service delivered to mobile terminals and base stations from the central office. Bidirectional transmission based on the scheme has been experimentally demonstrated. OCIS codes: (060.0060) Fiber optics and optical communications; (060.2330) Fiber optics communications Introduction Due to the increasing demand for in-door, high speed wireless access networks for next generation, millimeter-wave (MM-W) wireless-over-fiber (WoF) technology has been considered as a very promising solution. However, with the increasing of the carrier frequency up to 60GHz, the diameter of the coverage area of each base station (BS) is limited within tens of meters. As a consequence, numerous electrical local oscillator (LO) devices of high frequency are required in each BS and mobile terminal (MT), incurring high system complexity and cost. Hence, cost-effective microwave photonic techniques for frequency up-conversion have been developed for system integration In this paper, we propose a new CO-BS-MT architecture to construct a bidirectional 60GHz WoF system, while providing both remote BS and MT with LO service of high-quality from the CO. For the downlink transmission, frequency up-conversion via optical beating and self-heterodyne detection techniques have been utilized to transmit and receive MM-W signals, while eliminating the use of electrical LO generators in both BS and MT. For the uplink transmission, the high-frequency LO, which is required for data up-conversion in MT and the MM-W signal downconversion in BS, is provided by the centralized LO service distributed from CO, instead of relying on electrical LO generators in MT and BS. The stability and operational parameters of LO are pre-determined and controlled in CO. A proof-of-concept experiment is carried out to demonstrate the feasibility of the proposed scheme

Advanced optical networking technologies for next generation optical...

Issued as final reportBellSouth. Science and Technology Lab

Fiber-wireless convergence in next-generation communication networks: systems, architectures, and management

This book investigates new enabling technologies for Fi-Wi convergence. The editors discuss Fi-Wi technologies at the three major network levels involved in the path towards convergence: system level, network architecture level, and network management level. The main topics will be: a. At system level: Radio over Fiber (digitalized vs. analogic, standardization, E-band and beyond) and 5G wireless technologies; b. Network architecture level: NGPON, WDM-PON, BBU Hotelling, Cloud Radio Access Networks (C-RANs), HetNets. c. Network management level: SDN for convergence, Next-generation Point-of-Presence, Wi-Fi LTE Handover, Cooperative MultiPoint. • Addresses the Fi-Wi convergence issues at three different levels, namely at the system level, network architecture level, and network management level • Provides approaches in communication systems, network architecture, and management that are expected to steer the evolution towards fiber-wireless convergence • Contributions from leading experts in the field of Fiber-Wireless Convergence

Pulse response of multimode interference devices

© 2006 IEEE.This is a a joint IEEE/OSA publication. The definitive version of this paper is available at: http://dx.doi.org/10.1109/JLT.2005.863278DOI: 10.1109/JLT.2005.863278Multimode interference (MMI) devices operating at high data rates are important in optical interconnects and optical networks. Their 1× N splitting provides a fundamental functionality in these and other applications. To determine the speed limitations of MMI devices, the ultrashort pulse response of these devices is modeled. For example, for 50-fs Gaussian input pulses into a 1 × 16 splitter, the output pulses are severely degraded in coupling efficiency (48%) and completely broken up in time primarily due to intermodal and intramodal (waveguide) dispersion. Material dispersion is found to play only a minor role in the pulse response of MMI devices. However, for 1-ps input pulses into the same 1 × 16 splitter, the output pulses are only moderately degraded in coupling efficiency (86%) and only slightly degraded in shape

Precision measurements for propagation properties of high-definition polymer waveguides by imaging of scattered light

©2008 SPIE--The International Society for Optical Engineering. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The electronic version of this article is the complete one and can be found online at: http://dx.doi.org/10.1117/1.2842390DOI: 10.1117/1.2842390We present a reliable, nondestructive, and real-time technique for characterization of propagation properties of planar optical waveguides based on accurately imaging the scattered light from the optical waveguide using a sensitive charge-coupled device (CCD) camera with built-in integration functionality. This technique can be used for real-time investigation of the propagation properties (loss, mode profile, bending properties, etc.) as well as the fabrication quality of planar optical waveguides. With this technique, we evaluate high-definition polymer optical waveguides on printed circuit board (PCB) substrates with a very low loss of 0.065dB/cm at a wavelength of 850nm, and measurement accuracy is less than 0.01dB/cm. We expect this technique with the given CCD camera to be suitable for reliably measuring loss coefficients well below 0.1dB/cm