Planar photonic chips with tailored angular transmission for high-contrast-imaging devices

AbstractA limitation of standard brightfield microscopy is its low contrast images, especially for thin specimens of weak absorption, and biological species with refractive indices very close in value to that of their surroundings. We demonstrate, using a planar photonic chip with tailored angular transmission as the sample substrate, a standard brightfield microscopy can provide both darkfield and total internal reflection (TIR) microscopy images with one experimental configuration. The image contrast is enhanced without altering the specimens and the microscope configurations. This planar chip consists of several multilayer sections with designed photonic band gaps and a central region with dielectric nanoparticles, which does not require top-down nanofabrication and can be fabricated in a larger scale. The photonic chip eliminates the need for a bulky condenser or special objective to realize darkfield or TIR illumination. Thus, it can work as a miniaturized high-contrast-imaging device for the developments of versatile and compact microscopes.

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Planar photonic chips with tailored angular transmission for high-contrast-imaging devices

10.21203/rs.3.rs-646324/v1 ◽

2021 ◽

Author(s):

Yan Kuai ◽

Junxue Chen ◽

Gang Zou ◽

Joseph Lakowicz ◽

Douguo Zhang

Keyword(s):

Large Scale ◽

Biological Species ◽

High Contrast ◽

Contrast Imaging ◽

Imaging Device ◽

Low Contrast ◽

High Contrast Imaging ◽

Brightfield Microscopy ◽

Photonic Band ◽

Microscopy Images

Abstract A limitation of standard brightfield microscopy is its low contrast images, especially for thin specimens of weak absorption, and biological species with refractive indices very close in value to that of their surroundings. Here, we demonstrate, using a planar photonic chip with tailored angular transmission as the sample substrate, a standard brightfield microscopy can provide both darkfield and total internal reflection (TIR) microscopy images with one experimental configuration. The image contrast is enhanced without altering the specimens and the microscope configurations. This planar chip consists of several multilayer sections with designed photonic band gaps and a central region with dielectric nanoparticles, which does not require top-down nanofabrication and can be fabricated in a large scale. The photonic chip eliminates the need for a bulky condenser or special objective to realize darkfield or TIR illumination. Thus, it can work as a miniaturized high-contrast-imaging device for the developments of versatile and compact microscopes.

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Developments in TEM for life-science research

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010017030x ◽

1994 ◽

Vol 52 ◽

pp. 514-515

Author(s):

U. Lücken ◽

Wim M. Busing ◽

Michael Felsmann ◽

Frank de Jong ◽

Max T. Otten

Keyword(s):

Life Science ◽

Materials Science ◽

Focal Length ◽

Science Research ◽

Objective Lens ◽

High Contrast ◽

Contrast Imaging ◽

Low Contrast ◽

High Contrast Imaging ◽

Small Spot

The study of Life Science materials with the TEM faces a number of problems such as low contrast in unstained specimens and specimen sensitivity to electron-beam damage and poor vacuum. Providing solutions to these problems has been the basis for several new developments on the Philips CM-series TEMs.Objective lenses traditionally have been optimised for parameters that are important in materials science: high resolution and very small spot sizes. With these parameters comes a short focal length which reduces the contrast from the specimen - no problem in the high-contrast materials science specimens, but highly problematic in the case of low-contrast biological specimens. A new objective lens - the BioTWIN - has been developed specifically for high-contrast imaging and analysis of biological specimens. Its long focal length (6.2 mm; 2 to 3 times larger than that of a typical materials science objective lens) ensures high contrast by enabling the removal of the majority of elastically and inelastically scattered electrons by the objective aperture. Figure 1 shows a comparison of images of a stained section imaged at low magnification, recorded with a TWIN and a BioTWIN lens.

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Two cold belts in the debris disk around the G-type star NZ Lupi

Astronomy and Astrophysics ◽

10.1051/0004-6361/201935135 ◽

2019 ◽

Vol 625 ◽

pp. A21 ◽

Cited By ~ 6

Author(s):

A. Boccaletti ◽

P. Thébault ◽

N. Pawellek ◽

A.-M. Lagrange ◽

R. Galicher ◽

...

Keyword(s):

Scattered Light ◽

Planetary Systems ◽

High Angular Resolution ◽

High Contrast ◽

Contrast Imaging ◽

Nearby Star ◽

Imaging Device ◽

High Contrast Imaging ◽

Debris Disk ◽

Dust Distribution

Context. Planetary systems hold the imprint of the formation and of the evolution of planets especially at young ages, and in particular at the stage when the gas has dissipated leaving mostly secondary dust grains. The dynamical perturbation of planets in the dust distribution can be revealed with high-contrast imaging in a variety of structures. Aims. SPHERE, the high-contrast imaging device installed at the VLT, was designed to search for young giant planets in long period, but is also able to resolve fine details of planetary systems at the scale of astronomical units in the scattered-light regime. As a young and nearby star, NZ Lup was observed in the course of the SPHERE survey. A debris disk had been formerly identified with HST/NICMOS. Methods. We observed this system in the near-infrared with the camera in narrow and broad band filters and with the integral field spectrograph. High contrasts are achieved by the mean of pupil tracking combined with angular differential imaging algorithms. Results. The high angular resolution provided by SPHERE allows us to reveal a new feature in the disk which is interpreted as a superimposition of two belts of planetesimals located at stellocentric distances of ~85 and ~115 au, and with a mutual inclination of about 5°. Despite the very high inclination of the disk with respect to the line of sight, we conclude that the presence of a gap, that is, a void in the dust distribution between the belts, is likely. Conclusions. We discuss the implication of the existence of two belts and their relative inclination with respect to the presence of planets.

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The CM120 Biotwin: a high-contrast objective lens, optimum cryo-vacuum and improved EDX performance

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100139299 ◽

1995 ◽

Vol 53 ◽

pp. 584-585

Author(s):

Uwe Lücken ◽

Michael Felsmann ◽

Wim M. Busing ◽

Frank de Jong

Keyword(s):

Life Science ◽

Focal Length ◽

Objective Lens ◽

High Contrast ◽

Contrast Imaging ◽

X Ray ◽

Forming Mechanism ◽

Similar Image ◽

High Contrast Imaging ◽

Low Concentrations

A new microscope for the study of life science specimen has been developed. Special attention has been given to the problems of unstained samples, cryo-specimens and x-ray analysis at low concentrations.A new objective lens with a Cs of 6.2 mm and a focal length of 5.9 mm for high-contrast imaging has been developed. The contrast of a TWIN lens (f = 2.8 mm, Cs = 2 mm) and the BioTWTN are compared at the level of mean and SD of slow scan CCD images. Figure 1a shows 500 +/- 150 and Fig. 1b only 500 +/- 40 counts/pixel. The contrast-forming mechanism for amplitude contrast is dependent on the wavelength, the objective aperture and the focal length. For similar image conditions (same voltage, same objective aperture) the BioTWIN shows more than double the contrast of the TWIN lens. For phasecontrast specimens (like thin frozen-hydrated films) the contrast at Scherzer focus is approximately proportional to the √ Cs.

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