Modern instruments for molecular diagnostics are continuously optimized for diagnostic accuracy, versatility and throughput. The latest progress in LED technology together with tailored optics solutions allows developing highly efficient photonics engines perfectly adapted to the sample under test. Super-bright chip-on-board LED light sources are a key component for such instruments providing maximum luminous intensities in a multitude of narrow spectral bands. In particular the combination of white LEDs with other narrow band LEDs allows achieving optimum efficiency outperforming traditional Xenon light sources in terms of energy consumption, heat dissipation in the system, and switching time between spectral channels. Maximum sensitivity of the diagnostic system can only be achieved with an optimized optics system for the illumination and imaging of the sample. The illumination beam path must be designed for optimum homogeneity across the field while precisely limiting the angular distribution of the excitation light. This is a necessity for avoiding spill-over to the detection beam path and guaranteeing the efficiency of the spectral filtering. The imaging optics must combine high spatial resolution, high light collection efficiency and optimized suppression of excitation light for good signal-to-noise ratio. In order to achieve minimum cross-talk between individual wells in the sample, the optics design must also consider the generation of stray light and the formation of ghost images. We discuss what parameters and limitations have to be considered in an integrated system design approach covering the full path from the light source to the detector.
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.
For the first time nearly bandwidth-limited 10-fs laser pulses centered at 790 nm are generated in a Ti:sapphire ring resonator. Intracavity dispersion control is provided by dispersive dielectric mirrors together with the insertion of small amounts of intracavity glass path. Mode- locking is self-starting without the use of an aperture.