Magnetic fluid-based Tunable Mirror Sensitivity using Michelson Interferometer
Nidhi Mehta, Rucha P Desai*
Department of Physical Sciences, P. D. Patel Institute of Applied Sciences,
Charotar University of Science and Technology, CHARUSAT Campus, Changa
Magnetic fluid (ferrofluid) is a colloidal suspension of superparamagnetic particles that have been coated with a surfactant such as lauric or oleic acid and dispersed in a magnetically passive liquid. The current experiment is focused on the construction of a tunable mirror based on magnetic fluid. We exhibit a tunable mirror in our laboratory using custom-made magnetic fluid. The tunable mirror was created by applying a steady magnetic field to a magnetic fluid based on transformer oil (Ms = 250 G). The designed magnetic fluid-based mirror reflects> 95-97% at a magnetic field strength of 4 kG. Additionally, the application potential of the constructed adjustable mirrors was evaluated by utilizing them in a Michelson interferometer setup. The mechanical (i.e., sound) waves were applied to the experimental setup to determine the Michelson interferometer's sensitivity in the open and close system. The sensitivity of the Michelson interferometer having a conventional mirror with arm length 0.5 m is 1.82 ×10-8𝑚/√𝐻𝑧 in close system and 1.52×10-8𝑚/√𝐻𝑧 in open system at 100 Hz. Whereas the sensitivity of the magnetic fluid-based mirror is 8.57×10-9𝑚/√𝐻𝑧 in close system and 8.42×10-9𝑚/√𝐻𝑧 in open system at 100 Hz. In an open atmosphere, the magnetic fluid remains stable for more than six months. As a result, magnetic fluid-based tunable mirrors have been identified as a possible low-cost replacement to solid mirrors. The Michelson interferometer with magnetic fluid-based tunable mirror has various possible applications ranging from security to medical devices and allied spectroscopic techniques. Magnetic fluid is used optically in various applications, including tunable gratings, monochromators, adaptive liquid lenses, and tunable mirrors.