Microscope with Enhanced Depth of Field and 3–D Capability

Courtney-Pratt, J. S.; Gregory, RL

doi:10.1364/ao.12.002509

Cited by 22 publications

(8 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This chromatic aberration also is undesirable, and designs are normally geared toward its elimination (Downs 1981, Torok andHarvey 1984). However, it has been shown that the chromatic aberration effects can be used to enhance the depth of field of an optical microscope (Courtney-Pratt 1973. 1976) and has been made the basis of a noncontact optical probe, spectroscope, and profilometer (Molesini 1984.…”

Section: Aberrations In Optical Systemsmentioning

confidence: 99%

“…A surface profiling technique utilizing chromatic aberration of the microscope objective has been shown to be practical (Courtney-Pratt 1976, Courtney-Pratt andGregory 1973) and can be extended to the confocal scanning microscopy method of surface profiling. It has been suggested that the chromatic aberration of the microscope objective in the CSLM can be exploited (Kino and Corle 1989) and Boyde (1987) has made use of the depth resolution of confocal optics in producing colour-coded stereo images on the TSRLM.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Confocal surface profiling utilizing chromatic aberration

Browne¹,

Akinyemi

Boyde

1992

Scanning

View full text Add to dashboard Cite

A new method for surface profiling in the confocal microscope utilizing chromatic aberration is presented. An expression for the integrated spectral intensity in the new profilometer is derived and chromatic aberration in the confocal microscope is explained. Estimates of the minimum resolvable depth and the maximum depth that can be profiled are given utilizing a ratiometric signal detection scheme. Examples of ratio images illustrating the new surface profiling technique are presented, showing the scheme to be both simple to implement and effective.

show abstract

Section: Aberrations In Optical Systemsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Confocal surface profiling utilizing chromatic aberration

Browne¹,

Akinyemi

Boyde

1992

Scanning

View full text Add to dashboard Cite

show abstract

“…6,7 Previous bifocal microscopes have either modified the objective by the insertion of a birefringent element or they used objectives that were designed for large chromatic aberration, 8 so that images are formed in different polarizations or wavelengths. 6,7 Previous bifocal microscopes have either modified the objective by the insertion of a birefringent element or they used objectives that were designed for large chromatic aberration, 8 so that images are formed in different polarizations or wavelengths.…”

Section: Introductionmentioning

confidence: 99%

Performance characteristics of a dual focus x-ray alignment microscope

Feldman¹

1995

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

View full text Add to dashboard Cite

We report a dual focus alignment microscope which we have implemented on our Anorad x-ray exposure tool. The microscope uses an Olympus 50ϫ, 0.55 numerical aperture extra-long-working distance objective and newly developed optics to obtain simultaneous images of the mask and wafer. The images are nearly diffraction limited, have high brightness, uniform intensity to 5% full width at half-maximum, and are telecentric. They may be viewed either sequentially or superimposed on a charge coupled device video camera. We have used conventional image processing techniques to locate individual vertical and horizontal x-ray mask and oxide level wafer features to about 15 nm, 3. This is much less than the 500 nm optical resolution of the microscope. The dual focus imaging avoids the very precise high-speed mechanical motion conventionally required to refocus the microscope objective. In addition, vibration induced offsets are eliminated by acquiring the mask and wafer images simultaneously. These offsets can be serious in systems in which the mask and wafer are locked together, even if the vibration is at a level which causes negligible deterioration of the resolution. We have observed that waveform errors of /20, much better than required for diffraction limited performance, lead to image distortions of about 25 nm. These distortions can be corrected either in software or by using very high-quality optics. We expect consideration of all these effects will be required to align far below the optical resolution.

show abstract

“…The distortion introduced by light microscope systems has been studied by several authors; more recently the analysis has been extended to optical serial sectioning systems. Early work in optical serial sectioning and related techniques was considered by Burke et al (1971), Hausler (1972) and Courtney-Pratt & Gregory (1973). Stoksetch (1969) gave an expression for the twodimensional microscope transfer function subsequently used in iterative algorithms for reconstructing serial section images (Agard, 1984;Castleman, 1979).…”

Section: Introductionmentioning

confidence: 99%

Improvement in the resolution of three-dimensional data sets collected using optical serial sectioning

Garza¹,

Diller²,

Bovik³

et al. 1989

Journal of Microscopy

View full text Add to dashboard Cite

In this paper an approach for improving the quality of 3-D microscopic images obtained through optical serial sectioning is described and implemented. A serially sectioned image is composed of a sequence of 2-D images obtained by incrementing the focusing plane of the microscope through the specimen of interest; ideally, the image obtained at each focusing plane should be in focus, and should contain information lying only within that plane. In practice, however, the images obtained contain redundant information from neighbouring focusing planes and are blurred by a three-dimensional low-pass distortion. These degradations are a consequence of the limited aperture of any optical system; using principles of geometric optics and allowing for the passage of light through the specimen, we are able to demonstrate that the microscope distortion can be described as a linear system, if the absorption of the specimen is assumed to be linear and non-diffractive. The transfer function of the microscope is found to zero a biconic region of 3-D spatial frequencies orientated along the optical axis; a closed-form expression is derived for the low-pass transfer function of the microscope outside the region of missing frequencies. The planar resolution of the serial sections can be greatly improved by convolving the image obtained with the inverse of the low-pass distortion function, although the missing cone of frequencies is not recoverable. The reconstruction technique is demonstrated using both simulated images, to demonstrate more clearly the effects of the distortion and the accuracy of the subsequent reconstruction, and actual experiments with a pollen grain and a stained preparation of human cerebellum tissue.

show abstract

Microscope with Enhanced Depth of Field and 3–D Capability

Cited by 22 publications

References 0 publications

Confocal surface profiling utilizing chromatic aberration

Confocal surface profiling utilizing chromatic aberration

Performance characteristics of a dual focus x-ray alignment microscope

Improvement in the resolution of three-dimensional data sets collected using optical serial sectioning

Contact Info

Product

Resources

About