Low loss (approximately 6.45dB/cm) sub-micron polycrystalline silicon waveguide integrated with efficient SiON...

Area of Science:

• Photonics and Optical Engineering
• Materials Science

Background:

• Silicon photonics relies on efficient waveguide fabrication for integrated circuits.
• Polycrystalline silicon (poly-Si) offers a CMOS-compatible material for waveguide development.
• Minimizing propagation and coupling losses is crucial for device performance.

Purpose of the Study:

• To fabricate and characterize sub-micron single-mode poly-Si waveguides.
• To integrate poly-Si waveguides with SiON waveguide couplers.
• To measure propagation and coupling losses for TE mode in the C-band.

Main Methods:

• Deep UV lithography for waveguide fabrication.
• Integration with SiON waveguide couplers.
• Optical measurements of propagation loss and fiber coupling loss.

Main Results:

• Sub-micron poly-Si single-mode waveguides were successfully fabricated and integrated.
• Propagation loss for TE mode in the C-band was measured at approximately 6.45 ± 0.3 dB/cm.
• Coupling loss with polarization-maintaining fiber (PMF) was approximately 3.4 dB/facet for TE mode.
• Poly-Si waveguides with SiON cladding showed lower propagation loss compared to SiO2 cladding.

Conclusions:

• The fabricated poly-Si waveguides exhibit competitive propagation loss values.
• SiON cladding is a promising alternative to SiO2 for reducing losses in poly-Si waveguides.
• These findings contribute to the advancement of silicon photonics technology.