Efficient erbium-doped thin-film lithium niobate waveguide amplifiers

Area of Science:

• Photonics and optical communications
• Materials science
• Integrated optics

Background:

• Lithium niobate on insulator (LNOI) is a promising platform for integrated photonics.
• Active waveguide amplifiers are crucial for LNOI but currently lacking.
• Existing LNOI devices lack essential components for signal amplification.

Purpose of the Study:

• To develop and demonstrate an efficient waveguide amplifier on the LNOI platform.
• To integrate active amplification capabilities into LNOI photonic circuits.
• To address the need for essential building blocks in LNOI technology.

Main Methods:

• Fabrication of erbium-doped LNOI waveguides using crystal growth and ion slicing.
• Lithography-based techniques for precise waveguide patterning.
• Characterization of amplifier performance under optical pumping.

Main Results:

• Demonstrated a compact 5 mm long waveguide amplifier.
• Achieved a net gain of over 5 dB at 1530 nm signal wavelength.
• Required a low pump power of 21 mW at 980 nm.

Conclusions:

• The developed LNOI waveguide amplifier is efficient and compact.
• This work introduces a key component for future LNOI photonic integrated circuits.
• The amplifier is suitable for optical communications, nonlinear optics, and microwave photonics.