Topological insulator laser: Experiments

Area of Science:

• Photonics
• Condensed Matter Physics
• Materials Science

Background:

• Topological insulators exhibit robust transport properties due to topological invariants, making them resistant to defects and disorder.
• Exploiting topological phenomena in photonics has been a recent focus for developing robust optical systems.
• Existing topological systems often require magnetic fields or lack practical device applications.

Purpose of the Study:

• To demonstrate a nonmagnetic topological insulator laser system with topologically protected transport.
• To investigate the lasing properties, including mode stability and efficiency, of such a system.
• To explore the use of S-chiral microresonators for unidirectional lasing in active topological platforms.

Main Methods:

• Fabrication of a nonmagnetic topological insulator laser system.
• Utilizing S-chiral microresonators to engineer unidirectional light propagation.
• Characterization of lasing properties, including mode spectrum, robustness to defects, and slope efficiency.

Main Results:

• The topological insulator laser system exhibited topologically protected transport within the cavity.
• Single-mode lasing and significant robustness against defects were observed.
• The system achieved considerably higher slope efficiencies compared to topologically trivial counterparts.
• Unidirectional lasing was achieved without the need for external magnetic fields.

Conclusions:

• The developed nonmagnetic topological insulator laser system offers robust single-mode lasing and enhanced efficiency.
• The use of S-chiral microresonators enables controlled unidirectional lasing, highlighting the potential of active topological platforms.
• This research opens avenues for the development of novel active topological devices with unique functionalities.