Harmonic and Intermodulation Performance of Sagnac Fiber-Optic Interferometer

Abstract

In this article, closed-form expressions are obtained for the amplitudes of the harmonic and intermodulation products generated when driving the fiber-optic Sagnac interferometer by a DC bias voltage plus an equal-amplitude two-tone signal. The results clearly show the strong dependence of the harmonic and intermodulation performance on the DC bias voltage and/or the phase bias of the fiber-optic Sagnac interferometer. The results obtained suggest that the DC bias voltage and/or the phase bias play an important role in deciding the linearity of the fiber-optic Sagnac interferometer and, hence, its suitability for analog applications.