ABSTRACT
Many of the laser imaging techniques share common key parameters with traditional methodologies, such as sample illumination, image recording, spatial resolution, contrast, “color” content, and so on. In this chapter, all these issues are addressed, highlighting similarities encountered in the various laser imaging modalities, but also stressing when a particular method requires special treatment. The chapter begins with a conceptional section, explaining and defining differences when using laser light rather than light from conventional sources in the imaging process. In particular, the approaches of point, line, and sheet illumination and scanning are discussed, together with issues of spectral information in the image (single, multispectral, or hyperspectral content). In the second part, issues of “sampling” are addressed, including problems associated with digitization of image data, spatial resolution, and spectral content; for all, key equations are provided to evaluate image quality. In the final part, the topic of “superresolution” beyond the Abbé limit is summarized, linking it to how the point-spread function (PSF) is treated. In particular, the two modalities of structured (spatially-patterned) superresolution PSF engineering (including SIM and STED) and single-molecule localization PSF mapping (including PALM STORM) are discussed, and what specific image generation and reconstruction methodologies are required.
