Bragg grating based biochemical sensor using submicron Si/SiO2 waveguides for lab-on-a-chip applications: a novel...

Area of Science:

• Photonics and optical sensing
• Biochemical sensing technologies
• Integrated optics

Background:

• Submicrometer waveguides are crucial for miniaturized optical devices.
• High refractive index contrast is key for enhanced sensor sensitivity.
• Existing biosensors often rely on metallic layers or bulky components.

Purpose of the Study:

• To propose and analyze a novel silica core Si-SiO(2) waveguide biochemical sensor.
• To optimize waveguide parameters for maximum sensitivity.
• To explore the sensor's performance for various refractive index samples.

Main Methods:

• Design and analysis of a submicrometer silica core Si-SiO(2) waveguide.
• Incorporation of a Bragg grating in the cladding region.
• Optimization of waveguide parameters for TE and TM modes.
• Sensitivity analysis for different ambient refractive indices.

Main Results:

• An optimum core width was identified for lower refractive index samples.
• TM mode configuration demonstrated significantly higher sensitivity (200-740 nm/RIU) for indices 1.33-1.63.
• The sensor achieved sensitivity comparable to surface plasmon polariton (SPP) based sensors.
• The proposed structure avoids metallic layers and bulky prisms, simplifying realization.

Conclusions:

• The novel waveguide sensor offers high sensitivity and is easily fabricated.
• Its simple structure and small dimensions facilitate integration with planar lightwave circuits.
• The device is suitable for lab-on-a-chip applications and advanced biochemical sensing.