An electromagnetic instrument transformer is a common device used to measure large current values in high-voltage electrical networks; it has been in use for more than a century. However, the optical current transformer, a promising technology also known as a fiber optic current sensor (FOCS), offers increased safety and ease of operation, as well as the absence of errors caused by the magnetic circuit of legacy transformers. Although the FOCS scheme is well known and has been actively developed for over a quarter century, it has certain disadvantages that limit its use. This paper describes the authors’ efforts to solve these problems in order to make FOCS technology competitive and widely adopted. We upgraded the FOCS optical circuit, expanded the frequency band of the captured current signal, and reduced the solution’s cost. We designed new signal processing algorithms to compensate for errors caused by internal factors in the measurement circuit, as well as those caused by environmental influences. We developed an FOCS computer model based on the Jones matrix formalism to enhance the experimental debugging. It allowed us to define the requirements for elements of the optical circuit and its production accuracy.

In the current article an advanced method of EFPI baseline measurement by use of spectral function approximation is proposed. The method provides an increase in EFPI baseline measurement precision and computational acceleration. The method bases on two foundations provided by analysis of low-finesse Fabry-Perot interferometer model: reduction of search domain and taking into account the most informative spectral intervals, providing a greater impact on the residual of measured and theoretical EFPI spectral functions. Proposed signal processing method resulted in the EFPI baseline measurement resolution less than 50 pm for the cavity length values between 20 and 700 μm.

For a multimode optical-fiber interferometer with a multichannel detector system, two alternative methods of signal processing in the presence of amplitude fading are studied theoretically and experim

A fiber-optic polarization interferometer with two electrooptic elements (sensor and additional modulator) designed for measuring electric field intensity is suggested and analyzed. The paper focuses...