Detector for terahertz electromagnetic waves

Detector for terahertz electromagnetic waves comprising:

• at least one first device that collects and transforms an incident electromagnetic wave having a terahertz frequency within a terahertz frequency band into a measurable mechanical response;
• and
• a detection device for detecting an output signal representative of the measurable mechanical response;
• said first device comprising a first element and an opposite element forming with the first element a capacitive gap;
• said first element being a mechanical resonator having a mechanical resonance frequency and being configured to response mechanically to the action of a force stemming from an electric field,
• said electric field being generated between at least one first electric pole induced in said first element, by first electric charges having a first electrical sign, and at least one second electric pole induced in said opposite element, by second electric charges having a second electrical sign opposite to the first electrical sign,
• wherein the first device is a terahertz optomechanical transducer that is a terahertz electromagnetic resonator made at least of metal, the terahertz optomechanical transducer comprising the first element and the opposite element,
• the first element and the opposite element each comprising a support layer and an electrically conductive layer that is a metal pattern,
• the first element and the opposite element having geometric characteristics and dimensions together:
• to define a given terahertz electromagnetic resonance frequency of the terahertz electromagnetic resonator, and
• to collect the incident terahertz electromagnetic wave being at the electromagnetic resonance frequency of the terahertz electromagnetic resonator or in the response frequency bandwidth of the terahertz electromagnetic resonator, and to transform the incident terahertz electromagnetic wave into a measurable mechanical response,
• the first element mechanically moves or deforms under the effect of the force stemming from the electric field generated by an interaction of the incident terahertz electromagnetic wave on electric charges present in the electromagnetic terahertz resonator and their mutual coupling,
• the electric field being generated by the interaction of said incident electromagnetic wave with electric charges in said terahertz electromagnetic resonator, at the terahertz frequency of the incident electromagnetic wave or in the response frequency bandwidth of the terahertz electromagnetic resonator,
• wherein the first electric charges and the second electric charges alternate in signs between the first and the second electric poles in time at the terahertz frequency of the incident electromagnetic wave, and
• wherein the mechanical resonance frequency of the mechanical resonator is much lower than the electromagnetic resonance frequency of the terahertz electromagnetic resonator the mechanical resonance frequency being in the kHz, MHz, or GHz domain.