Twin Cores Research Articles

Mismatched directional couplers

Various twin-core couplers composed of mismatched optical fibers are capable of complete power transfer over lengths only moderately longer than their matched analogs. Examples include tapered and piecewise-continuous mismatched couplers. These linear couplers also provide insight into the mechanism of nonlinear coupling because nonlinearity induces periodic mismatching betweén twin cores that are axially uniform.

Low Drift Push-Pull Self-Saturating Magnetic Amplifier Using a Single Core

Push-pull magnetic amplifiers using a single core are known for circumventing the problem of core matching, but these amplifiers have the following drawbacks: the extreme reduction of gain with the decrease of input resistance, low output power, etc. These problems can be solved by using two magnetic circuits of a stacked four-legged core structure as twin cores in the full-wave type of self-saturating magnetic amplifier. Experiments show that it is possible to obtain twin cores sufficiently well matched, because each leg is from the same sheet, and to decrease the thermal resistance between the twin cores by the yoke connecting between them. As a result it is evident that the use of a four-legged core can improve the zero drift caused mainly by the change of ambient temperature. With this four-legged core structure, the input magnetomotive force equivalent to the zero drift caused by the change of ambient temperature can be decreased by at least one order of magnitude, as compared with spiral core pairs.

Low drift push-pull self-saturating magnetic amplifier using a single core

Push-pull magnetic amplifiers using a single core are known for circumventing the problem of core matching, but these amplifiers have the following drawbacks: the extreme reduction of gain with the decrease of input resistance, low output power, etc. These problems can be solved by using two magnetic circuits of a stacked four-legged core structure as twin cores in the full-wave type of self-saturating magnetic amplifier. Experiments show that it is possible to obtain twin cores sufficiently well matched, because each leg is from the same sheet, and to decrease the thermal resistance between the twin cores by the yoke connecting between them. As a result it is evident that the use of a four-legged core can improve the zero drift caused mainly by the change of ambient temperature. With this four-legged core structure, the input magnetomotive force equivalent to the zero drift caused by the change of ambient temperature can be decreased by at least one order of magnitude, as compared with spiral core pairs.