As sophisticated optical imaging technologies move into clinical applications, manufacturers have to work according to a consistent quality management. We demonstrate the application of basic quality principles to camera-based biomedical optics for a variety of examples including molecular diagnostics, dental imaging, ophtalmology and digital radiography. Novel concepts in fluorescence detection and structured illumination will also be highlighted.
The metrology community traditionally used fixed telecentric lenses to do optical measurement. The need to investigate varying fields of view led to the use of several fixed magnification lenses; this approach eventually yielded to zoom lenses. The majority of zoom lenses are designed to hold one set of conjugates constant, usually the object and the image. Such zoom lenses typically have the entrance pupil internal to the zoom groups; thus varying in position during zooming. By placing a stop external to the zoom groups, a constant entrance pupil position can be achieved. This idea can be extended to a telecentric stop position, and hence a telecentric zoom lens.
Emission microscopy involves post-mortem analysis of integrated circuits. By applying an electric signal to faulty chips, infra-red emission occurs at sites of potential failure. The ability to examine entire chips has not been fully incorporated into the objective design of emission microscopes. This ability allows faster identification of trouble points. After failure-sites have been identified, they are more closely investigated by using higher power microscope objectives. A 0.8X lens having an numerical aperture of the object of 0.32 is discussed. This lens covers an object full field of view of 18.0 X 18.0 mm (diagonal of 25.5 mm) at 50% vignetting, reaching 25 X 25 mm (diagonal 35 mm) at 100% vignetting. Unique features include a 20 mm working distance for the insertion of analytic probes, a 100 mm gap between objective and decollimating lens groups for mounting issues, and a back focal length of 50 mm for introduction of filters, beam splitters and/or other auxiliary optics.