Lens resolution

Optical microscopes have one serious drawback, their resolution, resulting from the fundamental physics of lenses. Lord Rayleigh, over 100 years ago, defined the currently accepted maximum optical lens resolution to be one-half of the wavelength of the imaging radiation. In truth, conventional optical microscopy did not achieve this level of definition mainly because of out-of-focus light. This prevented the observation of atoms and single molecules. 

The determination of the overall resolution of some measuring equipment may require more efforts, as it involves the combination of the resolution of different measuring system components. For example, the optical resolution of optical measuring systems may be calculated by the combination of the resolution of different components (e.g., their MTF - modulation transfer functions), such as lens resolution, sensor resolution, data transmission resolution, and display resolution. 

HoUaday, JT, Ting, AC, Koester, CJ, Portney, V and WiUis TR, Silicone intraocular lens resolution in air and in water, J Catatact Refract Surg, 14, 657-659 (1988). El-Sherif, AE, Taweela, N and Nagi AK, Complete fiacture of urethral Foley s catheter a rare complication, J Royal Soc Med, 84, 563 (1991). 

Optical Imaging Lens resolution-can be sub-micron Limited to camera resolution, can be >1000 fps Lens field-of-view Yes—with a modified cell to allow optical access Accurate tool for flow for channel-level flow only. Catalyst layer images require alteration of the diffusion media and heat transfer boundary conditions. 

Plenary 8. J Grave et al, e-mail address J.Greve tn.utwente.nl (RS). Confocal direct unaging Raman microscope (CDIRM) for probing of the human eye lens. High spatial resolution of the distribution of water and cholesterol in lenses. 

The first corrected electron-optical SEM was developed by Zach [10]. Eor low-voltage SEM (LVSEM, down to 500 eV electron energy instead of the conventional energies of up to 30 keV) the spot size is extremely large without aberration correction. Combining and correction and a electrostatic objective lens, Zach showed that a substantial improvement in spot size and resolution is possible. The achievable resolution in a LVSEM is now of the order of 1-2 mn. More recently, Krivanek and colleagues succeeded in building a corrected STEM [53,M]. 

A point light source is imaged onto the specimen by the objective and the transmitted light collected by the collector lens and detected by a broad-area detector in the case of reflection microscopy, the objective lens also serves simultaneously as a collector (see figure Bl.18.10. The resolution is solely detennined by the objective lens, because the collector has no imaging fimction and only collects the transmitted light. The... 

Figure Bl.18.11. Confocal scanning microscope in reflection the pinliole in front of the detector is in a conjugate position to the illumination pinliole. This arrangement allows the object to be optically sectioned. The lens is used to focus the light beam onto the sample and onto the pinliole. Thus, the resulting point spread fimctioii is sharpened and the resolution increased.

The specimen is immersed in the next lens encountered along the column, the objective lens. The objective lens is a magnetic lens, the design of which is the most crucial of all lenses on the instrument. Instrumental resolution is limited primarily by the spherical aberration of the objective lens. 

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