Absorption of reflected substrate modes in Ti:LiNbO(3) waveguide systems.

Area of Science:

• Optoelectronics
• Materials Science
• Integrated Optics

Background:

• Integrated optical spectrum analyzers (IOSAs) are crucial for signal processing.
• Reflected substrate modes in LiNbO3 substrates can degrade IOSA performance.
• Minimizing these modes is essential for efficient device operation.

Purpose of the Study:

• To develop an optical system that reduces reflected substrate modes in IOSAs.
• To investigate the effectiveness of absorbing, multilayer interference coatings for this purpose.
• To assess performance across a broad range of incident angles at 830 nm.

Main Methods:

• Application of absorbing, multilayer interference coatings to the back sides of LiNbO3 substrates.
• Fabrication of an optical system incorporating these coated substrates.
• Experimental evaluation of the optical system's performance in an IOSA context.

Main Results:

• Substantial reduction in reflected substrate modes was achieved.
• The optical system demonstrated effectiveness over a broad range of incident angles.
• Performance was specifically validated for devices operating at 830 nm.

Conclusions:

• Absorbing, multilayer interference coatings are effective in mitigating reflected substrate modes.
• This technique offers a viable solution for enhancing the performance of LiNbO3-based IOSAs.
• The developed optical system provides improved signal integrity for optical spectrum analysis.