Retarded response of the optical transmittance through a magnetic fluid film under switching-on/off external magnetic fields

Time dependence of light transmission in nanoparticle ferrofluids

“…the fluid transparency increases. This process takes place very quickly and can be described as a charging process [4]. Accordingly, the change in light transmission with time during the initial process is given…”

“…It has been observed that chain-like structures in magnetic liquids give rise to a decrease in the light transmission. In this case, the change of light transmission with time is described by a discharging process [4] T / expðÀt=t 2 Þ…”

“…Nowadays the use of nano-or micro-sized magnetic particles in biomedical area has intensively studied, and several techniques utilizing magnetic particles in magnetic separation, drug delivery, and imaging have been proposed [2]. The time dependence of light transmission through magnetic liquid films upon the application of static magnetic field was the subject of many studies [3,4]. In these studies, the observed time dependence of light transmission was attributed due to cluster formation.…”

Observation of magneto-optical effect in extremely dilute ferrofluids under weak magnetic field

“…Consequently, the hydrodynamic, magnetic, and optical properties of the fluids can be effectively magnetically modulated [3][4][5][6]. In the past decade, much attention has been focus on its versatile magneto-optical effects, such as static magnetic birefringence, dichroism, and magnetically tunable refractive index, because of their broad applications in various functional optical devices, e.g., sensors, switches, modulators, and photonic crystal fiber [7][8][9][10][11]. On the other hand, investigation on ferrofluids is also nontrivial from the theoretical point of view.…”

Agglomeration response of nanoparticles in magnetic fluid via monitoring of light transmission

“…Magnetic fluids (MFs), which are suspensions of magnetic nanosized particles enwrapped by surfactant, have attracted a great deal of attention due to their rich and versatile phenomena under an external magnetic field [1][2][3][4][5][6]. In the past decade, construction of photonic devices based on MF films, such as tunable gratings [7], tunable fiber modulators and filters [8][9][10], optical switches [11,12], and fieldinduced anisotropy [13], has been the subject of research. The physical picture behind these photonics devices is the chain agglomeration of nanoparticles in MF under an external magnetic field, which is related to the optical features of MF, such as its refractive index, absorption, and birefringence.…”