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A tractable method for accurately predicting the parasitic capacitance of a field coil as part of an all-fiber Mach-Zehnder interferometric switch based on Faraday rotation is reported. The effects of the wire insulation layer, inter-turn air gap as well as capacitive coupling to the four nearest adjacent turns are considered in predicting the effective parasitic capacitance for single-layer coils. The complex distributed capacitance network that results is resolved using Kron reduction to yield the equivalent shunt capacitance. Several coil configurations were designed and compared to experimental results. This new approach can be used in conjunction with existing expressions for inductance and loss to enable the complete and accurate a priori design of field generating coils. Index Terms--All-fiber devices, coils, Faraday rotation, magneto-optic switching.

Recently there has been increasing concern regarding the effects of low-frequency magnetic fields on humans and livestock. A portable magnetometer is essential for monitoring the field dose encountered. There are some devices currently available for this purpose which use the induced EMF technique. The field sensitivity for these devices depends on the number of turns of coil used. This limits the minimum size of devices with reasonable performance. The magnetometer considered in this paper overcomes this size limitation by using a highly magnetostrictive material, Terfenol-D, as the magnetic field sensor. The primary focus of this paper is to determine the magnetic field spectral characteristics using digital signal processing. A survey of spectral estimation techniques are presented, followed by their application to the Terfenol-D magnetic field signal. The estimators are compared using data obtained from a magnetometer hardware prototype. Using these methods it was possible to detect signal for a field strength of 20 milligauss.

This paper introduces some physical layer requirements of electro-optical as well as all optical networking. Due to the huge volume of data that is transmitted on these networks, there is a need for high-speed switching with effective switching in the nanosecond regime or better. While such switches exist for electronic media, they have been challenging for optical applications. Taking the recent developments in magneto-optical switches into consideration, there is a pressing need for fast switching of highly inductive loads. The state-of-the-art as well as the trends and needs for high speed switching in optical networks are presented. Some of the newest developments in the small-scale high-speed switching for electro-optical and all optical light path applications will also be presented. Experimental results of the newly developed switches at our program are presented and discussed. Based on the results, system requirements are identified and some shortcomings of the initial system are addressed. Possible improvements to the overall light-trail system are proposed and discussed. Index Terms--Faraday effect, magnetic switches, optical communication, optical switches.

An all-fiber interferometric switch based on Faraday rotation exhibited by magneto-optic materials in the presence of an external magnetic field is reported. The interferometer is Mach-Zehnder type and the related phase shift was obtained by the rotation of the state of polarization of a linearly polarized optical signal. The operation of the switch is demonstrated experimentally. The effect of the optical beam size on the achievable Faraday rotation is also investigated. Hysteresis is avoided as the magnetic field required for switching is much lower than the saturation field. Index Terms--All-fiber devices, Faraday rotation, fiber-based magneto-optics, Mach-Zehnder interferometer, optical beam size, optical switches.

Magneto-optical switching using Faraday rotation is investigated for optical fiber networks. Nonlinearity of the Faraday rotation was measured, and the optical switch was designed accordingly. The device was implemented experimentally with promising results. Index Terms--All-fiber switch, Faraday effect, magneto-optic switching.

Achieving network transparency via the use of all-optical devices is vital for next generation DWDM networks to realize fundamental functions such as switching, routing and wavelength conversion. With the abundance of capacity created by the Internet boom of the '90s, emphasis is placed on both device performance and cost. A 1 x 1 integrated switch based on the polarization plane rotation of light in Bi-substituted iron garnets is reported here using a Mach-Zehnder interferometer to achieve amplitude modulation by use of suitable material dimensions and field strengths. The working principle, design and fabrication of the switch are detailed. [ABSTRACT FROM AUTHOR]

A tractable method for accurately predicting the parasitic capacitance of a field coil as part of an all-fiber Mach-Zehnder interferometric switch based on Faraday rotation is reported. The effects of the wire insulation layer, inter-turn air gap as well as capacitive coupling to the four nearest adjacent turns are considered in predicting the effective parasitic capacitance for single-layer coils. The complex distributed capacitance network that results is resolved using Kron reduction to yield the equivalent shunt capacitance. Several coil configurations were designed and compared to experimental results. This new approach can be used in conjunction with existing expressions for inductance and loss to enable the complete and accurate a priori design of field generating coils. [ABSTRACT FROM AUTHOR]

This paper introduces some physical layer requirements of electro-optical as well as all optical networking. Due to the huge volume of data that is transmitted on these networks, there is a need for high-speed switching with effective switching in the nanosecond regime or better. While such switches exist for electronic media, they have been challenging for optical applications. Taking the recent developments in magneto-optical switches into consideration, there is a pressing need for fast switching of highly inductive loads. The state-of-the-art as well as the trends and needs for high speed switching in optical networks are presented. Some of the newest developments in the small-scale high-speed switching for electro-optical and all optical light path applications will also be presented. Experimental results of the newly developed switches at our program are presented and discussed. Based on the results, system requirements are identified and some shortcomings of the initial system are addressed. Possible improvements to the overall light-trail system are proposed and discussed. [ABSTRACT FROM AUTHOR]