Characterization of a Functional Hydrogel Layer on a Silicon-Based Grating Waveguide for a Biochemical Sensor.

Area of Science:

• Materials Science
• Biomedical Engineering
• Optics and Photonics

Background:

• Refractive index (RI) sensors are crucial for biochemical detection.
• Silicon-based grating waveguides offer a platform for integrated optical sensing.
• Functional hydrogels can provide specific molecular recognition capabilities.

Purpose of the Study:

• To numerically demonstrate the characteristics of functional hydrogel layers on silicon-based grating waveguides.
• To explore the use of these structures as simple, cost-effective refractive index biochemical sensors.
• To establish design rules for hydrogel-assisted grating waveguide sensors.

Main Methods:

• Numerical simulation of grating waveguide characteristics.
• Modeling of refractive index changes in functional hydrogel layers.
• Analysis of transmission spectral shifts based on hydrogel properties.

Main Results:

• The effective refractive index change is dependent on hydrogel thickness, functional volume ratio, and functional strength.
• Transmission spectral profile shifts correlate with refractive index changes.
• The study confirms the feasibility of the proposed sensor design.

Conclusions:

• Functional hydrogel layers on silicon grating waveguides are feasible for biochemical sensing.
• Design parameters like thickness and functional strength significantly impact sensor performance.
• This approach offers a pathway for developing simple, cost-effective biochemical sensors.