Packaged whispering gallery resonator device based on an optical nanoantenna coupler

Area of Science:

• Photonics and Optical Engineering
• Nanotechnology
• Materials Science

Background:

• Whispering gallery mode (WGM) resonators are crucial for compact optical devices.
• Efficient coupling and environmental protection remain challenges for WGM devices.
• Optical nanoantennas offer potential for precise light manipulation.

Purpose of the Study:

• To present a packaged WGM device integrating a nanoantenna coupler and a microsphere resonator.
• To demonstrate the functionality of a WGM microlaser within a protected package.
• To evaluate the performance and characteristics of the integrated system.

Main Methods:

• Fabrication of microspheres from SiO2 or Er3+-doped fiber.
• Integration of a microsphere resonator with an optical nanoantenna coupler.
• Packaging of the WGM device within a glass capillary for environmental isolation.
• Characterization of lasing emission and coupling efficiency.

Main Results:

• Successful fabrication of a packaged WGM device with a nanoantenna coupler and microsphere resonator.
• Demonstration of a WGM laser with a low threshold of 93 µW at 1531 nm using Er3+-doped fiber.
• Maintained high quality (Q-) factor of approximately 10^8 in the packaged system.
• Achieved unidirectional coupling and collection of lasing emission via the nanoantenna.

Conclusions:

• The packaged WGM device offers a robust solution for integrated photonics.
• The nanoantenna-coupled microsphere system enables efficient WGM lasing and coupling.
• The device provides environmental isolation, small size, and high Q-factor, suitable for advanced optical applications.