Terahertz nonreciprocal isolator based on a magneto-optical microstructure at room temperature

Area of Science:

• Terahertz (THz) photonics
• Spintronics
• Materials science

Background:

• Nonreciprocal devices are crucial for signal isolation in optical systems.
• Terahertz (THz) technology requires compact, efficient isolators operating at room temperature.
• Indium Antimonide (InSb) exhibits promising magneto-optical properties for THz applications.

Purpose of the Study:

• To investigate the terahertz (THz) nonreciprocal circularly polarized transmission in a thin, longitudinally magnetized InSb film.
• To explore the non-eigen nonreciprocal transmission mechanism in InSb at room temperature.
• To design and optimize a THz isolator for linear polarized waves based on this effect.

Main Methods:

• Experimental investigation of THz transmission through magnetized InSb film.
• Utilizing orthogonal artificial birefringence gratings to enhance nonreciprocity.
• Device optimization through parameter tuning.

Main Results:

• Demonstrated THz nonreciprocal transmission in InSb film at room temperature.
• Achieved high isolation of 24 dB in the designed THz isolator.
• Obtained low insertion loss of less than 0.5 dB.
• Device operates effectively under a low magnetic field.

Conclusions:

• The non-eigen nonreciprocal transmission mechanism in InSb is viable for THz isolator applications.
• The developed THz isolator offers excellent performance metrics at room temperature.
• This work paves the way for practical THz nonreciprocal devices.