Enabling hyperspectral acquisition for Scanning Laser Optical Tomography

Scanning Laser Optical Tomography (SLOT) is a three-dimensional imaging technique usable on a micro- to mesoscale. The technique is equivalent to computer tomography, using a laser instead of x-rays. With this technology, a set of two-dimensional images is acquired at different angles and subsequently processed into volume information by reconstruction algorithms. Different contrast mechanisms can be used, depending on the application. Up until now transmission, scattering, fluorescence and second harmonic generation have been established for SLOT imaging. All of these contrast mechanisms are coupled to a specific narrow bandwidth, which is determined before the acquisition starts and is dependent on the setup and application. In order to collect true hyperspectral information, a spectrometer and a broadband light source have been integrated. This way, the amount of information is increased with each measurable wavelength, leading to various improvements of the SLOT technology. The entire transmission and absorption spectra of three-dimensional samples can now be measured and reconstructed. Here, we present the current state of development of the hyperspectral SLOT. This includes the technical construction of the hardware setup and the development of the software integration. Many challenges need to be overcome when implementing spectroscopy in a tomographic setup. Solutions to specific problems, such as decreased resolution and focal shift, will be presented. Finally, we will show the first results of hyperspectral SLOT imaging.