High harmonics produced in aligned molecules contain the structural information of bound-state electronic states. We
have produced high harmonics from N2 molecules aligned to arbitrary directions with 5-degrees steps. From the set of
high harnionic spectra, we have successfully reconstructed tomographic images of the highest occupied molecular
orbital (HOMO) of N2.
High harmonics produced in aligned molecules contain the structural information of the outermost electron orbital that preferentially ionizes in intense laser fields. We show a method to reconstruct a 3-dimensional (3D) structure of the molecular orbital. The method is based on the technologies to align molecules and to produce attosecond XUV pulses, both of which utilize intense ultrashort laser pulses. We measured a set of high harmonic spectra produced in differently aligned N2 molecules, and successfully reconstructed the image of the highest occupied molecular orbital (HOMO) with sub-angstrom resolution.