Ultraviolet transparent silicon oxynitride waveguides for biochemical microsystems.

Area of Science:

• Optical engineering
• Spectroscopy
• Materials science

Background:

• The ultraviolet (UV) wavelength region is crucial for chemical analysis via absorption spectroscopy.
• Germanium-doped silica waveguides, common in telecommunications, have limitations in UV light guidance below 400 nm due to UV-absorbing centers.

Purpose of the Study:

• To investigate the UV performance of silicon oxynitride (SiO(x)N(y)) waveguides.
• To demonstrate the applicability of these waveguides in biochemical microsystems for absorption measurements.

Main Methods:

• Fabrication and characterization of silicon oxynitride (SiO(x)N(y)) waveguides.
• Measurement of propagation loss in the UV-Vis spectrum (220-550 nm).
• Integration of waveguides with microfluidic channels for biochemical analysis.

Main Results:

• Silicon oxynitride (SiO(x)N(y)) waveguides demonstrated very good UV performance.
• Propagation loss was measured at approximately 1.0 dB/cm for 24-microm -wide waveguides in the 220-550 nm range.
• Successful absorption measurements of propranolol were performed at 212-215 nm, with a detection limit of 13 microM.

Conclusions:

• Silicon oxynitride (SiO(x)N(y)) waveguides are suitable for UV absorption spectroscopy.
• The integration with microfluidic channels enables sensitive biochemical analysis.
• These waveguides offer a viable alternative to germanium-doped silica for UV applications.