Terahertz modulation system and method of modulating a terahertz signal

A method of modulating a terahertz signal, the method comprising:

• emitting a terahertz signal along a path and across a terahertz interacting surface of an electromechanical transducer;
• modulating at least a portion of said terahertz signal by moving said terahertz interacting surface of said electromechanical transducer in back-and-forth sequences between first and second positions across said path, said moving resulting from actuating said electromechanical transducer with a modulation signal;
• and
• synchronously measuring said modulated portion of said terahertz signal using said modulation signal, and generating a differential signal indicative thereof.

A terahertz time-domain derivative spectrometer for analyzing a sample, the terahertz time-domain derivative spectrometer comprising:

• a terahertz signal emitter emitting a terahertz signal along a path extending across said sample, said terahertz signal having an electric field of a given amplitude and a given phase varying over time;
• a terahertz interacting surface receiving said terahertz signal and moving in back-and-forth sequences between first and second positions upon actuation with a modulation signal;
• a terahertz signal detector synchronously measuring said modulated portion of said terahertz signal using the modulation signal, and generating a differential signal indicative of a derivative of said varying amplitude over time;
• a controller performing a time-domain spectroscopic measurement on said sample based on said differential signal, including retrieving at least one of the given amplitude and the given phase varying over time.