Low-loss tantalum pentoxide photonics with a CMOS-compatible process

Area of Science:

• Photonics
• Materials Science
• Integrated Optics

Background:

• Tantalum pentoxide (Ta2O5) is a promising material for integrated photonic circuits.
• Reducing propagation loss and understanding thermal properties are crucial for practical applications.
• Existing photonic platforms often face challenges with loss and thermal stability.

Purpose of the Study:

• To report the performance of a Ta2O5 photonic platform.
• To investigate the propagation loss across different wavelengths.
• To characterize the thermal properties and absorption loss of Ta2O5 waveguides.

Main Methods:

• Fabrication of Ta2O5 waveguides with a process temperature below 350°C.
• Measurement of propagation loss at 1550 nm, 780 nm, and 2000 nm.
• Thermal bistability measurements across the entire C-band to determine absorption loss.
• Characterization of the temperature response of the Ta2O5 waveguides.

Main Results:

• Achieved propagation losses of 0.49 dB/cm at 1550 nm, 0.86 dB/cm at 780 nm, and 3.76 dB/cm at 2000 nm.
• First-time measurement of thermal bistability in the C-band for Ta2O5 waveguides, revealing absorption loss.
• Demonstrated favorable thermal stability of the Ta2O5 waveguides.
• Low fabrication temperature (<350°C) is compatible with optoelectronic integration.

Conclusions:

• The Ta2O5 photonic platform exhibits competitive propagation loss and excellent thermal stability.
• The study provides valuable data for minimizing waveguide loss in Ta2O5 devices.
• The low fabrication temperature facilitates integration with active optoelectronic components, paving the way for advanced photonic integrated circuits.