Functional dopant profiling of optical coherent transient materials

A new novel method that functionally maps the distribution of dopants in a photon echo material is proposed that relies on imposing a set of linear orthogonal gradient magnetic fields for a controlled hyperfine splitting of energy levels to create characteristic quantum beats when illuminated with a laser pulse with sufficient bandwidth to interrogate these levels. In this approach, a spectroscopic finger print of the dopant sites due to concentration and field susceptibilities in the sample is achieved through a Fourier decomposition of the radiative relaxation decay in an approach analogous to nuclear magnetic resonance (NMR) spectroscopy due to the imposition of a controlled spatial–spectral encoding scheme. An example of such an interrogative approach uses a three pulse stimulated sequence necessary to probe a gradient resolved voxel. This three pulse approach can be combined with the conventional confocal imaging technique to provide information about the underlying chemistry of dopant distribution along each imaging plane which is useful in guiding the design and manufacturing process of optical crystals. In combination with gradient induced quantum beats, the entire inhomogeneous bandwidth can be interrogated. The proposed approach would scan this entire bandwidth at much faster rate enabling characterization of a large number of crystals than is currently possible through mechanical scanning with a confocal microscopy based spectroscopic technique as well as providing functional dopant profiling which is not currently possible with conventional approaches.