Highly Sensitive Liquid M-Z Waveguide Sensor Based on Polymer Suspended Slot Waveguide Structure

Area of Science:

• Photonics
• Integrated Optics
• Chemical Sensing

Background:

• Integrated waveguide optical sensors offer enhanced sensitivity and reduced detection limits.
• Slot waveguide structures are crucial for improving sensor performance.
• Suspended structures can enhance optical field interaction with analytes.

Purpose of the Study:

• To propose and analyze a polymer Mach-Zehnder interferometer (MZI) optical sensor based on a slot waveguide structure.
• To investigate the impact of structural parameters on sensor performance at 1550 nm.
• To enhance sensor accuracy through improved optical field-analyte interaction.

Main Methods:

• Design and simulation of a polymer MZI optical sensor incorporating a suspended slot waveguide.
• Analysis of the effects of single waveguide width, slot width, and coupling structure.
• Optimization of MZI parameters including branch spacing, arm length, branch span, and slot region size.
• Ensuring single-mode transmission for optimal performance.

Main Results:

• The designed MZI sensor features a branch spacing of 10 µm, arm length of 2045 µm, branch span of 700 µm, and slot region of 500 µm.
• Achieved an average sensitivity of 972.1 dB/RIU.
• Obtained an average detection resolution of 1.6 × 10^-6 RIU.
• Demonstrated performance improvements of 1.5x, 1.6x, and 2.1x compared to suspended strip, non-suspended slot, and non-suspended strip waveguides, respectively.

Conclusions:

• The proposed suspended slot waveguide MZI sensor significantly enhances sensitivity and detection resolution.
• The design optimizes optical field-analyte interaction for superior sensing accuracy.
• This technology holds promise for advanced integrated optical sensing applications.