PUBLICATIONS IN SCIENTIFIC JOURNALS & CONFERENCE PROCEEDINGSMARCH 2009 - OFC/NFOEC 2009Tunable GPON Receivers Enable Phased Migration to 1Gb/s per Subscriber Robert Murano, Wayne F. Sharfin, Michael J. L. Cahill, and Jim Wernlund ABSTRACT — We demonstrate a tunable receiver with -30dBm sensitivity at 10^-10 BER on any of seven 100GHz spaced channels, and propose deployment strategies for low-cost migration to up to 1Gb/s per subscriber downstream Wavelength-Agile PON. FEBRUARY 2008 - OFC/NFOEC 2008Tunable 2.5Gb/s Receiver for Wavelength-Agile DWDM-PON Robert Murano, Wayne F. Sharfin, and Michael J. L. Cahill ABSTRACT — We demonstrate a low-cost, tunable receiver based on semiconductor thin film filters. A bit-error ratio of 10^-10 is demonstrated at a received optical power of -18 dBm in a three-channel, 2.488 Gb/s, DWDM test system. MARCH 2007 - OFC/NFOEC 2007Distribution of Embedded DWDM Channel Monitors in Pass-Through Node Limited Transmission Links Michael Cahill and Glenn D. Bartolini ABSTRACT — A transmission model is used to derive the requirements for distributing DWDM optical channel monitors in transmission links engineered with ROADM-based architectures, which can require up to 24 transparent pass-through nodes. The model applies random settings of variable parameters to reflect realistic optical transmission link budgets. It is shown that as the number of spans increase, DWDM channel monitors must be distributed more frequently, approaching an economical “tipping point” that may justify integrating channel monitors within optical amplifiers. AUGUST 2006 - SPIE PROCEEDINGSTunable Thin Film Filters for Intelligent WDM Networks Michael Cahill ABSTRACT — Optical transmission systems have evolved rapidly in recent years with the emergence of new technologies for gain management, wavelength multiplexing, tunability, and switching. WDM networks are increasingly expected to be agile,flexible, and reconfigurable which in turn has led to a need for monitoring to be more widely distributed within the network. Automation of many actions performed on these networks, such as channel provisioning and power balancing, can only be realized by the addition of optical channel monitors (OCMs). These devices provide information about the optical transmission system including the number of optical channels, channel identification, wavelength, power, and in some cases optical signal-to-noise ratio (OSNR). Until recently OCMs were costly and bulky and thus the number of OCMs used in optical networks was often kept to a minimum. We describe a family of tunable thin film filters which have greatly reduced the cost and physical footprint of channel monitors, making possible 'monitoring everywhere' for intelligent optical networks which can serve long haul, metro and access requirements from a single technology platform. As examples of specific applications we discuss network issues such as auto provisioning, wavelength collision avoidance, power balancing, OSNR balancing, gain equalization, alien wavelength recognition, interoperability, and other requirements assigned to the emerging concept of an Optical Control Plane. SEPTEMBER 2004 - OSA MEETING ON OPTICAL INTERFERENCE COATINGSTunable Thin Film Filters Using Thermo-Optic Silicon Lawrence H. Domash ABSTRACT — Thin film tunable filters without moving parts use thermo-optic effects in PECVD amorphous silicon. Demonstrations include single and multiple cavity tunable filters, and fixed wavelength switchable WDM add/drop filters using hybrid dielectric / semiconductor cavities. JUNE 2004 - OSA MEETING ON OPTICAL INTERFERENCE COATINGSLow-cost optical monitoring for DWDM systems Glenn D. Bartolini ABSTRACT — this paper we present a very stable low-cost integrated tunable thin-film filter and photodiode with a form-factor appropriate for installation into optical amplifiers, providing additional performance information to the local amplifier and the network management system. The performance characteristics of the tunable filter and the performance of the filter when measuring optical spectra are discussed. We describe and analyze several performance improvements derived from knowledge of the optical spectrum within amplifiers. JANUARY 2004 - JOURNAL OF LIGHTWAVE TECHNOLOGYTunable and Switchable Multiple-Cavity Thin Film Filters Lawrence H. Domash, Ming Wu, Nikolay Nemchuk, Eugene Ma ABSTRACT — A family of thin film interference filters is described that incorporates amorphous silicon layers for wide thermo-optic tunability and the potential for multiple cavity designs. Plasma enhanced chemical vapor deposition (PECVD) of hydrogenated amorphous silicon (a-Si:H) onto fused silica or crystalline silicon wafer substrates produces films with high index, low loss at 1500 nm , and thermo-optic index coefficients approximately ten times larger than those of the dielectric materials typically used in wavelength division multiplexing (WDM) filters. MARCH 2003 - OSA OPTICAL AMPLIFIER CONFERENCESwitchable thin film add/drop filter Lawrence Domash, Ming Wu, Nikolay Nemchuck, and Robert Murano ABSTRACT — A five-cavity, 117 layer, 200GHz thin film add/drop filter fabricated from combined dielectric / semiconductor materials is thermo-optically switched between transmission and reflection at a fixed channel 1548.3 nm with a contrast ratio 18.4 dB. MARCH 2003 - OSA OPTICAL FIBER CONFERENCETunable thin film filters Lawrence H. Domash, Eugene Ma, Nikolay Nemchuk, Adam Payne, and Ming Wu ABSTRACT — We report widely tunable thin film filters, including both single-cavity and multi-cavity designs, based on thermo-optic effects in thin films of amorphous semiconductors deposited by PECVD. Applications include an optical channel monitor packaged in a TO can. JUNE 2002 - PHOTONICS NORTHTunable thin-film filters based on thermo-optic semiconductor films Lawrence H. Domash, Eugene Ma, Nikolay Nemchuk, Adam Payne, and Ming Wu ABSTRACT — Thermo-optic layers of thin film semiconductors are deposited by PEVCD to create thermally tunable bandpass filters for WDM optical networks. Amorphous semiconductor films, adapted from the solar cell and display industries, are the primary ingredient. Single-cavity tunable filters with FWHM as small as 0.085 nm, >40 nm tuning range, and insertion losses ranging 0.2-4 dB depending in design have demonstrated. Key enablers for this new family of index-tunable thin film devices are PECVD deposition, large internal temperature changes >400C, high conductivity polysilicon heater films, and extremely robust film adhesion. Applications include optical monitoring, add/drop multiplexing, dynamic gain equalization, and dispersion compensation. |