An integrated parity-time symmetric wavelength-tunable single-mode microring laser

Area of Science:

• Photonics
• Laser Physics
• Integrated Optics

Background:

• Stable single-mode operation in ring lasers is crucial for various applications.
• Achieving precise mode control and wavelength tunability remains a challenge in microring laser design.

Purpose of the Study:

• To propose and experimentally demonstrate an electrically pumped parity-time (PT)-symmetric microring laser.
• To achieve precise mode control for stable single-mode operation.
• To enable wavelength-tunable single-mode lasing with an improved mode suppression ratio.

Main Methods:

• Implementation of a photonic integrated circuit with two mutually coupled active microring resonators.
• Incorporation of multiple semiconductor optical amplifiers to achieve PT-symmetry by manipulating gain and loss.
• Integration of phase modulators for continuous wavelength tuning.

Main Results:

• Demonstration of single-mode lasing at 1,554.148 nm.
• Achieved a side-mode suppression ratio exceeding 36 dB.
• Exhibited continuous wavelength tunability from 1,553.800 to 1,554.020 nm.

Conclusions:

• The proposed PT-symmetric microring laser enables precise mode control and stable single-mode operation.
• The device offers significant improvements in mode suppression ratio.
• This technology provides a pathway for developing tunable single-mode lasers for integrated photonic applications.