Research On Wavelength Accumulation Effects Of Reflection-induced Retardance Upon BGOCS Systems

Optical Current Sensor, OCS for short, is the kind of equipment measuring current directly or indirectly by utilizing optical technology. Bulk Glass Optical Current Sensor, BGOCS for short, is one kind of OCS, and the research on it has good achievement in recent years.Reflection-induced retardance, one of the factors affecting the BGOCS performance, has dispersion features. Therefore, there will be a wavelength accumulation effect in the systems employing broad-band optical sources. It has not been proved how much this effect can affect the broad-band system up till now. However, the problem whether it is reasonable and feasible to use a monochromatic light model to describe broad-band systems is concerned nowadays, so it is necessary to do research on it. The dispersion formula of the reflection-induced retardance is given first, and then, its wavelength accumulation effect upon a bulk glass optical current sensor are theoretically analyzed and digitally simulated. The results show that the wavelength accumulation effect of the reflection-induced retardance is less enough and the treatment of using monochromatic model to describe broad-band systems is reasonable and feasible, if the wavelength accumulation effects of other optical parameters of the sensing head are not considered. The results might be a reference to the colleagues working in the area of bulk glass optical current sensing techniques.Meanwhile, because of the practical requirements on the researching process of this thesis, the methods of measuring the practical optical parameters of quarter waveplates are introduced in this paper, including: measuring the practicalretardance value of quarter waveplates (not including integral times In ), determining its fast and slow axes, and measuring the refractive indices of its fast and slow axes, which have improved the measurement accuracy of the linear birefringence in the sensing head of the BGOCS, and have certain signification in the areas of theory and engineering practice for the waveplate measurement technology.