Enhanced Circular Dichroism Spectroscopy Utilizing a Novel Chiral Cladding Fiber Sensor

Chiral substances demonstrate handedness by interacting with other chiral entities, like circularly polarized light. Circular dichroism (CD) spectroscopy, the conventional technique for determining the handedness of enantiomers, is based on the unequal absorption of various circularly polarized lights. We have previously introduced an innovative method using a waveguide to ascertain the handedness of enantiomers introduced into the core of an optical fiber. However, the main drawback of that sensor was the practical challenge of introducing chiral material into the fiber core. In this article, we address this issue and present an enhanced, more feasible approach. This new method offers a marked enhancement over traditional CD spectroscopy responses by increasing their differential output signal. Our study employs chiral material as the cladding layer in an optical fiber setup, assessing how lifting degeneracy impacts cutoff frequencies. We insert a cylindrical achiral core into the chiral solution being examined, and no need to add other chiral and achiral structures or nanoparticles to increase sensitivity. The CD parameter displays contrasting signs for right- and left-handed chiral substances. Additionally, by measuring the variance in cutoff frequencies, we can deduce the magnitude of chirality by weakly guiding approximation. This suggested sensor is versatile and suitable for various materials possessing a nonzero chirality parameter across different frequency ranges.