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Structured illumination has been employed in fluorescence microscopy to extend its lateral resolution. It has been demonstrated that a factor of 2 improvement can be achieved. In this paper, we introduce a novel optical arrangement that can further improve the resolution. It makes use of a fine grating held in close proximity to the sample. The fringe pattern thus projected onto the sample contains grating vectors substantially higher than those that are possible with the conventional structured illumination setup. We will present experimental results to demonstrate the principle of the technique, and will show that, theoretically, it can achieve an imaging NA approaching 4. [c] 2010 Optical Society of America OCIS codes: 180.2520, 050.6624, 110.4850, 350.5730.

We have demonstrated recently that, by using an ultrastable optical interferometer together with artificial neural networks (ANNs), track widths down to 60 nm can be measured with a 0.3 NA objective lens. We investigate the effective conditions for training ANNs. Experimental results will be used to show the characteristics of the training samples and the data format of the ANN inputs required to produce suitably trained ANNs. Results obtained with networks measuring double tracks, and classifying different structures, will be presented to illustrate the capability of the technique. We include a discussion on expansion of the application areas of the system, allowing it to be used as a general purpose instrument. OCIS codes: 120.3180, 120.3940, 120.4640, 200.4260.

We describe a numerical vector diffraction model based on Mie theory that describes the imaging of spherical particles by bright-field, confocal, and interferometric microscopes. The model correctly scales the amplitude-scattered field relative to the incident field so that the forward-scattered and incident light can be interfered to correctly model imaging with copolarization transmission microscopes for the first time to our knowledge. The model is used to demonstrate that amplitude and phase imaging with an interferometric microscope allows subwavelength particle sizing. Furthermore, we show that the phase channel allows much smaller particles to be sized than amplitude-only measurements. The model is validated by experimental measurements. OCIS codes: 180.1790, 180.3170, 120.5050, 290.5820, 290.5850.