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    Area of Science:

    • Terahertz (THz) technology
    • Optical metrology
    • Laser physics

    Background:

    • Continuous-wave (CW) terahertz (THz) systems are valuable for material characterization.
    • Existing systems can be complex and costly.
    • Frequency modulation techniques offer potential for enhanced performance.

    Purpose of the Study:

    • To propose and evaluate a novel CW THz homodyne system.
    • To leverage a dual-mode laser (DML) for efficient THz wave generation.
    • To demonstrate a cost-effective and robust THz measurement solution.

    Main Methods:

    • Utilized a dual-mode laser (DML) with fast and stable wavelength tuning.
    • Implemented a homodyne detection scheme.
    • Generated frequency-modulated THz waves using the DML.

    Main Results:

    • Demonstrated a cost-effective and robust CW THz system operation.
    • Successfully applied the system for measuring sample thickness.
    • Successfully applied the system for measuring sample refractive index.

    Conclusions:

    • The proposed CW THz homodyne system, inspired by FMCW methods, is effective.
    • The use of a DML enables compact and fast THz measurement systems.
    • This scheme has potential for various THz applications requiring precise measurements.