A magneto-optical fiber device based on magnetic fluid-filled photonic crystal fiber

Abstract

Magneto-optical fiber plays an important role in magneto-optical devices. The fiber has larger Verdet constant will lead to a larger Faraday rotation per unit length fiber and applied field. In order to increase the magneto-optical characteristic, especially the Verdet constant of photonic crystal fiber, a magneto-optical fiber device based on combination of the magnetic fluid and the tunable photonic bandgap effect of photonic crystal fiber is proposed. The magnetic fluid is filled into the air holes of the cladding layer in the photonic crystal fiber using a new air pressure-filled method. Because the magnetic fluid prepared in this experiment has higher refractive index (>1.45), and is filled into the air-holes of photonic crystal fiber, as a result, the index guiding fiber is converted into photonic bandgap fiber. A magneto-optic system based on the Stokes polarization parameters method is designed which could analyze the Faraday effect. The corresponding Faraday rotation could be measured in the external magnetic field with different magnetic intensity by this magneto-optic system. The Faraday rotation of the photonic crystal fiber filled with magnetic fluid is approximately 5 times than that of the single mode optical fiber. The proposed magneto-optical fiber device takes full advantage of the ultrahigh sensitivity characteristic of photonic bandgap fiber and the large Verdet constant of magneto-optical fiber, can be used for high sensitive magnetic field sensor, magneto-optical switch, and magneto-optical modulator, etc.

High Precision Measurements Lend No Supporting Evidence of Previously Reported Large Verdet Constants for Olive Oil

“…al., 2013 ) 1) the dispersion of the Verdet constant for the Wild Oats sample of olive oil shows no enhancement in the red spectral region of interest ( Figure 3) and appears as "normal" magnetic rotatory dispersion, when compared to other common substances. 2) all samples tested at ~650nm, which is near the wavelength where the significantly large value of the Verdet constant was reported, show no correspondingly large values (Table 3). 3) a variety of laser powers (CW mode) were tested on several brands to eliminate possible non-linear optical effects for the laser power reported, even if unlikely at such CW laser powers, and no anomalous responses were measured.…”