Optimization in nanocoated D-shaped optical fiber sensors.

Area of Science:

• Photonics and Optical Sensing
• Materials Science

Background:

• Nanocoated D-shaped optical fibers are established as sensitive sensor platforms.
• Lossy mode resonance (LMR) is a key phenomenon in these devices.

Purpose of the Study:

• To investigate the optimization of nanocoating parameters for enhanced LMR characteristics.
• To improve the figure of merit (FOM) of nanocoated D-shaped optical fiber sensors.
• To explore the potential for polarizer-free operation in optical filters and sensors.

Main Methods:

• Systematic variation of nanocoating width, thickness, and refractive index.
• Analysis of optical spectra to observe and characterize LMR.
• Optimization of coating properties to isolate specific resonances and reduce spectral width.

Main Results:

• Optimizing nanocoating width, thickness, and refractive index effectively reduces the full width at half minimum (FWHM) of LMR.
• Multiple resonances can arise from modes guided within the nanocoating under specific conditions.
• Selective isolation of resonances by tuning coating width and imaginary refractive index enhances the FOM.
• Design strategies enable simultaneous resonance centering for TE and TM polarizations, eliminating polarizer requirements.

Conclusions:

• Nanocoating optimization is crucial for improving the performance of D-shaped optical fiber sensors.
• The ability to control LMR and polarization dependence opens avenues for advanced optical filter and sensor development.
• Achieving high FOM and polarizer-free operation signifies a notable advancement in optical sensing technology.