Abstract: A system includes a first laser beam including a pulsed laser emanating from the instrument propagates in the air, wherein the first lase beam is tuned to the wavelength at which a target chemical absorbs, its pulses bringing molecules to an excited state, a second laser beam used to probe target chemicals by transient absorption spectroscopy, wherein the second laser beam is pulsed or continuous, and a detector.

Abstract: A system includes a first laser beam including a pulsed laser emanating from the instrument propagates in the air, wherein the first lase beam is tuned to the wavelength at which a target chemical absorbs, its pulses bringing molecules to an excited state, a second laser beam used to probe target chemicals by transient absorption spectroscopy, wherein the second laser beam is pulsed or continuous, and a detector.

Abstract: A method and apparatus to characterize a shape of an isomeric form of a sample comprised of a molecule or a cluster of molecules. The method includes raising an electron of the sample to a Rydberg state having an orbital diameter sufficient to encompass at least a portion of the sample; further raising the electron to an ionization state and correlating the energy required to transition from the Rydberg state to the ionization state with the three dimensional structure of the sample. In a preferred embodiment raising the electron to the Rydberg state includes raising the electron to a first Rydberg state Ry1, and then raising the electron to a second Rydberg state Ry2. Further raising the electron to the ionization state includes raising the electron from the Ry2 state to the ionization state using optical excitation, and correlating the energy considers at least a wavelength of the optical excitation.