A method for determining a set of physical parameters of a sample, comprising the steps of: A Retrieving a measured sample temporal trace Es(t), B retrieving a measured reference temporal trace Eref(t), C determining an widened reference temporal trace, called Eref0(t), and determining a discrete Fourier transform {hacek over (E)}.sub.ref0(ω) of the widened reference temporal trace D determining a modeling of an impulse response of the sample in the frequency domain, depending on the set of physical parameters (pi), called sample frequency model {hacek over (E)}.sub.model{Pi}(ω), from the Fourier Transform of the widened reference temporal trace {hacek over (E)}.sub.ref0(ω)and a physical behavior model of the sample, E applying an optimization algorithm on the set of physical parameters (pi) comprising the sub steps of: E1 initializing physical parameters (pi), -realizing iteratively the sub steps of: E2 calculating an inverse discrete Fourier transform of the sample frequency model {hacek over (E)}.sub.model{Pi}(ω), called estimated sample temporal trace E.sub.est{Pi}(t), E3 calculating an error function (ε.sub.er{pi}), until obtaining a set of values (pi.sub.opt) of physical parameters minimizing said error function.

A method for determining a set of physical parameters of a sample, comprising the steps of: A Retrieving a measured sample temporal trace Es(t), B retrieving a measured reference temporal trace Eref(t), C determining an widened reference temporal trace, called Eref0(t), and determining a discrete Fourier transform {hacek over (E)}.sub.ref0(ω) of the widened reference temporal trace D determining a modeling of an impulse response of the sample in the frequency domain, depending on the set of physical parameters (pi), called sample frequency model {hacek over (E)}.sub.model{Pi}(ω), from the Fourier Transform of the widened reference temporal trace {hacek over (E)}.sub.ref0(ω)and a physical behavior model of the sample, E applying an optimization algorithm on the set of physical parameters (pi) comprising the sub steps of: E1 initializing physical parameters (pi), -realizing iteratively the sub steps of: E2 calculating an inverse discrete Fourier transform of the sample frequency model {hacek over (E)}.sub.model{Pi}(ω), called estimated sample temporal trace E.sub.est{Pi}(t), E3 calculating an error function (ε.sub.er{pi}), until obtaining a set of values (pi.sub.opt) of physical parameters minimizing said error function.

In an inspection system that uses terahertz waves, in order to improve the inspection precision for objects and the like, the inspection system has an illumination unit having a plurality of illumination elements that radiate terahertz waves; a camera unit that captures images of the terahertz waves that have been reflected off of an object that has been irradiated by the plurality of illumination elements; and a control unit that performs control so as to make the light emission timings for the plurality of illumination elements different.

Real-time multidimensional terahertz imaging system and method, the method comprising method for imaging an object, comprising, in a laser pump line: patterning a laser pump beam with known patterns of a radiation beam and illuminating the object with the radiation beam; yielding a patterned pump beam; directing the patterned beam from the pump line and a laser probe beam from a laser probe line to a detection crystal; single-shot detection of the radiation beam waveform; and correlating the single-shot detection and the known patterns.

A detector for detecting terahertz electromagnetic radiation comprises a substrate and a pair of electrically isolated detector elements supported thereon. Each detector element comprises a pair of antenna elements having a gap therebetween and a switch element comprising one or more pieces of photoconductive semiconductor material connected between the antenna elements across the gap. The pairs of antenna elements of the respective detector elements are configured so that, when the switch element is conductive, current is generated between the antenna elements by polarisation components of incident terahertz electromagnetic radiation having polarisation directions in respective sensing directions that are perpendicular, thereby providing simultaneous detection of perpendicular polarisation components of incident terahertz electromagnetic radiation.

A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse-jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

A chiral molecule can be defined as a molecule that has a non-superimposable mirror image. These mirror images can be referred to as enantiomers. The enantiomers generally have the same set of bond lengths and bond angles in their three-dimensional geometry. Apparatus and techniques described herein can be used to perform analysis of chiral molecules using cavity-enhanced molecular rotational spectroscopy. A sample cell can define a resonant cavity, and a sample introduction port can provide pulse-jet injection of an analyte molecule and a chiral tag to allow analysis of a complex comprising the analyte and chiral tag.

An apparatus and method for Crystal Anisotropy Terahertz Microscopy (“CATM”) is provided. The apparatus includes an emitter configured to emit a THz pulse and a detector configured to detect the THz pulse after the pulse is transmitted through a sample disposed on a sample surface of the detector. A pulsed radiation generator generates a probe beam to interrogate the detector. The detector may include an electro-optical (“EO”) crystal configured to change in birefringence according to the THz pulse. The sample surface of the detector may have a dielectric coating which is transmissive to THz and reflective to the probe beam. The sample is disposed on the dielectric coating.

Method and apparatus for non-invasive condition detection using an all fiber portable terahertz imaging system. An imaging system of the present disclosure may comprise a control module comprising a femtosecond pulsed laser configured to generate an output light beam, a dispersion compensation unit configured to receive the output light beam and transmit a laser light beam generated based upon the output light beam, a beam splitter configured to receive the laser light beam and divide the laser light beam into a pump light beam and a reference light beam; and a rapid scanning optical delay line configured to receive the pump light beam and transmit an exit light beam generated based upon the pump light beam, a patch probe comprising a transmitter module, an optics lens, and a detector module.

Method and apparatus for non-invasive condition detection using an all fiber portable terahertz imaging system. An imaging system of the present disclosure may comprise a control module comprising a femtosecond pulsed laser configured to generate an output light beam, a dispersion compensation unit configured to receive the output light beam and transmit a laser light beam generated based upon the output light beam, a beam splitter configured to receive the laser light beam and divide the laser light beam into a pump light beam and a reference light beam; and a rapid scanning optical delay line configured to receive the pump light beam and transmit an exit light beam generated based upon the pump light beam, a patch probe comprising a transmitter module, an optics lens, and a detector module.