High Speed Terahertz Modulator on the Chip Based on Tunable Terahertz Slot Waveguide

Area of Science:

• Terahertz (THz) science and technology
• Optoelectronics
• Semiconductor device physics

Background:

• Terahertz (THz) electromagnetic waves offer unique properties for various applications.
• Efficient and high-speed on-chip modulators and switches are crucial for THz systems.
• Existing THz modulation technologies often face limitations in speed, size, or operating conditions.

Purpose of the Study:

• To present a novel on-chip device for gigahertz-rate amplitude modulation and switching of broadband terahertz (THz) waves.
• To demonstrate the feasibility of using a tunable two-dimensional electron gas (2DEG) for THz wave control.
• To highlight the potential for compact, low-power, room-temperature THz modulators.

Main Methods:

• Device fabrication integrating a novel slot waveguide with an electronically tunable two-dimensional electron gas (2DEG).
• Characterization of THz wave propagation and modulation within the slot waveguide.
• Measurement of modulation depth, insertion loss, and modulation cutoff frequency.

Main Results:

• Achieved 96% THz intensity modulation at a 0.25 THz carrier frequency.
• Demonstrated low insertion loss and a compact device length of 100 microns.
• Exceeded a modulation cutoff frequency of 14 GHz, indicating high-speed modulation capability.

Conclusions:

• The developed on-chip device enables high-performance THz amplitude modulation and switching.
• The device operates efficiently at room temperature with low drive voltage and zero DC power consumption.
• The demonstrated architecture holds significant promise for next-generation on-chip THz modulators and switches.