A method of measuring a spectral response of a biological sample (1), comprises the steps generation of probe light having a primary spectrum, irradiation of the sample (1) with the probe light, including an interaction of the probe light and the sample (1), and spectrally resolved detection of the probe light having a modified spectrum, which deviates from the primary spectrum as a result of the interaction of the probe light and the sample (1), said modified spectrum being characteristic of the spectral response of the sample (1), wherein the probe light comprises probe light pulses (2) being generated with a fs laser source device (10). Furthermore, a spectroscopic measuring apparatus is described, which is configured for measuring a spectral response of a biological sample (1).

Methods and systems for determining water status in plant tissue are provided. A number of systems are capable of using terahertz signals to generate signals measuring total water content in plant tissue, including plant leaves. Using these signals, methods are capable of determining water status variables, including water mass per leaf area, relative water content, and leaf water potential, which can aid in agricultural, ecological, and environmental health, such as dehydration and droughst stress of plants.

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.

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.

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.

A terahertz scanner for detecting irregularities, such as chemical or structural variations, in a sample and methods of use thereof are described. The described terahertz scanner and algorithms allow for direct, high-sensitivity, high-throughput, and non-invasive detection of irregularities that range from chemical contaminant to material defects in a variety of substrates and settings.

A terahertz scanner for detecting irregularities, such as chemical or structural variations, in a sample and methods of use thereof are described. The described terahertz scanner and algorithms allow for direct, high-sensitivity, high-throughput, and non-invasive detection of irregularities that range from chemical contaminant to material defects in a variety of substrates and settings.

A terahertz device includes an antenna base including reflective films, wherein: the reflective films are curved to be recessed; the reflective film and the reflective film are arranged to be adjacent to each other in a y direction; and when viewed from a z direction, the sizes of the reflective film and the reflective film along an x direction are smaller than the sizes of the reflective film and the reflective film along the y direction.

A terahertz device includes an antenna base including reflective films, wherein: the reflective films are curved to be recessed; the reflective film and the reflective film are arranged to be adjacent to each other in a y direction; and when viewed from a z direction, the sizes of the reflective film and the reflective film along an x direction are smaller than the sizes of the reflective film and the reflective film along the y direction.