An imaging device includes: an area light source including an emission surface from which a sub-terahertz wave is emitted to a measurement target; and a detector including an image sensor that receives a reflected wave generated by the measurement target reflecting the sub-terahertz wave emitted from the emission surface. The area light source includes: at least one point light source that emits a sub-terahertz wave; and a reflector that reflects the sub-terahertz wave emitted from the at least one point light source, to generate a sub-terahertz wave to be emitted from the emission surface. The reflector has a reflection surface that is a bumpy surface which includes two or more frequency components in a spatial frequency range and whose roughness curve element mean length RSm is at least 0.3 mm.

An imaging device includes: an area light source including an emission surface from which a sub-terahertz wave is emitted to a measurement target; and a detector including an image sensor that receives a reflected wave generated by the measurement target reflecting the sub-terahertz wave emitted from the emission surface. The area light source includes: at least one point light source that emits a sub-terahertz wave; and a reflector that reflects the sub-terahertz wave emitted from the at least one point light source, to generate a sub-terahertz wave to be emitted from the emission surface. The reflector has a reflection surface that is a bumpy surface which includes two or more frequency components in a spatial frequency range and whose roughness curve element mean length RSm is at least 0.3 mm.

This disclosure relates to a method for measuring an electric field in the near-field region of an optically excited sample. The method includes optically exciting at least part of the sample. This step includes directing excitation light onto an interface between the sample and a medium. The excitation light is incident onto the interface under an angle of incidence such that total internal reflection of the excitation light occurs at the interface. The method further includes measuring the electric field using a terahertz near-field probe, wherein the terahertz near-field probe is positioned on one side of the interface and the excitation light approaches the interface on another side of the interface. This disclosure further relates to a system and computer program for measuring an electric field in the near-field region of an optically excited sample.

A sample signal amplification method using a terahertz band graphene absorber is provided. The method comprises: fabricating a graphene absorber through steps of metal evaporation, graphene transfer and the like; preparing sample solutions having different concentrations; dropwise adding a sample solution to the surface of the graphene absorber, and then drying in the air at room temperature; collecting terahertz time-domain signals of all sample points to be detected and reference sample points on the surface of the graphene absorber; and calculating absorption rates of all the sample points to be detected and the reference sample points according to the terahertz time-domain signals, and calculating the intensity change of an absorption peak according to the intensity value corresponding to the highest point of the absorption peak.

Provided is a high efficiency and high sensitivity particle capture type terahertz sensing system. The particle capture type terahertz sensing system includes a sensing substrate to capture particles, and a terahertz sensor to emit terahertz electromagnetic waves to the sensing substrate to sense the particles, wherein the sensing substrate includes a base substrate and a particle capture structure layer formed on the base substrate, the particle capture structure layer includes a plurality of slits for focusing the terahertz electromagnetic waves, the particle capture structure layer captures the particles in the plurality of slits using dielectrophoresis, and an area in which the terahertz electromagnetic waves converge to the plurality of slits matches an area in which the particles are captured in the plurality of slits through the dielectrophoresis.

Provided is a high efficiency and high sensitivity particle capture type terahertz sensing system. The particle capture type terahertz sensing system includes a sensing substrate to capture particles, and a terahertz sensor to emit terahertz electromagnetic waves to the sensing substrate to sense the particles, wherein the sensing substrate includes a base substrate and a particle capture structure layer formed on the base substrate, the particle capture structure layer includes a plurality of slits for focusing the terahertz electromagnetic waves, the particle capture structure layer captures the particles in the plurality of slits using dielectrophoresis, and an area in which the terahertz electromagnetic waves converge to the plurality of slits matches an area in which the particles are captured in the plurality of slits through the dielectrophoresis.

A system for prompt virus infection carriers detection/screening using THz spectroscopy, which comprises a micro/nano-antennas array implemented as an antenna chip of predetermined shape and size, that has the maximum aspect ratio of the capacitor gap being sensitive to both P and S polarization, the array consisting of a plurality of printed micro-antenna elements, each of which having an equivalent inductor L of printed inductors and an equivalent capacitor C defined by gaps between printed contacts the length of the capacitor and the dielectric constant of a filler being between the printed contacts, to thereby determine a resonant frequency of the antenna element, the gaps are formed essentially along the cross diagonals of the each antenna element, thereby obtaining maximal aspect-ratio between the length of the capacitor and the gap width, that maximizes and sharpen the resonance effect of the each micro-antenna element; at least one capsule for holding the chip with the antennas array in a fixed position, preferably at the center, the at least one capsule being at least partially transparent to THz radiation range; means for applying material containing samples of viruses/exhaled biological ingredients to be detected that are exhaled into the gaps, for altering the dielectric constant of the filler and the resonance frequency; a THz spectrometer for scanning the samples and detecting shifts in the resonance frequency induced by the presence of the exhaled viruses/biological ingredients; at least one processor for processing the detected shifts in the resonance frequency and associating different shifts with different types of viruses/biological ingredients. The size of the array is matched to the beam size of the spectrometer, such that the entire radiation collimated beam will be captured by the antennas array, thereby maximizing the signal to noise ratio and the dynamic range.

A system for prompt virus infection carriers detection/screening using THz spectroscopy, which comprises a micro/nano-antennas array implemented as an antenna chip of predetermined shape and size, that has the maximum aspect ratio of the capacitor gap being sensitive to both P and S polarization, the array consisting of a plurality of printed micro-antenna elements, each of which having an equivalent inductor L of printed inductors and an equivalent capacitor C defined by gaps between printed contacts the length of the capacitor and the dielectric constant of a filler being between the printed contacts, to thereby determine a resonant frequency of the antenna element, the gaps are formed essentially along the cross diagonals of the each antenna element, thereby obtaining maximal aspect-ratio between the length of the capacitor and the gap width, that maximizes and sharpen the resonance effect of the each micro-antenna element; at least one capsule for holding the chip with the antennas array in a fixed position, preferably at the center, the at least one capsule being at least partially transparent to THz radiation range; means for applying material containing samples of viruses/exhaled biological ingredients to be detected that are exhaled into the gaps, for altering the dielectric constant of the filler and the resonance frequency; a THz spectrometer for scanning the samples and detecting shifts in the resonance frequency induced by the presence of the exhaled viruses/biological ingredients; at least one processor for processing the detected shifts in the resonance frequency and associating different shifts with different types of viruses/biological ingredients. The size of the array is matched to the beam size of the spectrometer, such that the entire radiation collimated beam will be captured by the antennas array, thereby maximizing the signal to noise ratio and the dynamic range.

Embodiments are disclosed for terahertz spectroscopy and imaging in dynamic environments. In an embodiment, a method comprises using a sensor of an electronic device to determine an orientation of the electronic device. A transmitter of the electronic device emits an electromagnetic (EM) wave in a terahertz (THz) frequency band into a dynamic environment according to a power duty cycle that is determined at least in part by the orientation. A receiver of the electronic device receives a reflected EM wave from the environment. A spectral response of the reflected EM wave is determined that includes absorption spectra that is indicative of the transmission medium in the environment. The absorption spectra are compared with known absorption spectra of target transmission mediums. Based on the comparing, a particular target transmission medium is identified as being the transmission medium in the environment, and a concentration level of the identified target transmission medium in the environment is determined.

A system comprises: a radio frequency (RF) resonator comprising a cavity and a tuning element, the cavity having at least one port, and the tuning element having a length inside the cavity; a processor; a spectrum analyzer coupled to the at least one port, the spectrum analyzer to provide to the processor values of a resonance parameter, the resonance parameter indicative of a resonant wavelength of the RF resonator; and an automotive steering mechanism coupled to the tuning element.