Hi all,
It is a new cycle of Journal club again – this week I will be presenting on work that I did during Perth attachment.
“Exploring Fourier Holography for Phase Imaging Applications”
Date: 22 Nov
Time: 10.30am
Venue: pantry area
The location is tentative, maybe I can book the little discussion room in division office but not sure now, and will email again if there is an update.
Regards,
Shan
Tuesday, November 20, 2007
Tuesday, November 13, 2007
Journal club - Nov 15 2007
Title: Polarizatio-sensitive full-field optical coherence tomography
Gael Moneron,1 Albert-Claude Boccara,1 and Arnaud Dubois2,*
citation: OPTICS LETTERS / Vol. 32, No. 14 / July 15, 2007
Abstract: We present a polarization-sensitive full-field optical coherence tomography system that can produce highresolution images of the linear retardance and reflectivity properties of biological media. En face images can be delivered at a frame rate of 3.5 Hz by combination of interferometric images acquired by two CCD cameras in an interference microscope illuminated with a tungsten halogen lamp. Isotropic spatial resolution of 1.0 um achieved. The technique is demonstrated on ex vivo muscle tissues.
Date: Nov 15 2007
Venue: Division pantry area
Gael Moneron,1 Albert-Claude Boccara,1 and Arnaud Dubois2,*
citation: OPTICS LETTERS / Vol. 32, No. 14 / July 15, 2007
Abstract: We present a polarization-sensitive full-field optical coherence tomography system that can produce highresolution images of the linear retardance and reflectivity properties of biological media. En face images can be delivered at a frame rate of 3.5 Hz by combination of interferometric images acquired by two CCD cameras in an interference microscope illuminated with a tungsten halogen lamp. Isotropic spatial resolution of 1.0 um achieved. The technique is demonstrated on ex vivo muscle tissues.
Date: Nov 15 2007
Venue: Division pantry area
Monday, November 5, 2007
Journal Club - Mapping polymer birefringence in three-dimensions using a polarizing microscope with oblique illumination
Dear All,
I am going to discuss following interesting paper that talks about measuring 3D distribution of birefringence in the sample. It is interesting in its own right as a basic technique and seems to be a good method of visualizing microtubules during mitosis without any label .
Mapping polymer birefringence in three-dimensions using a polarizing microscope with oblique illumination
Michael Shribak and Rudolf Oldenbourg
Marine Biological Laboratory, Woods Hole, MA 02543, USA
ABSTRACT
We have been developing a polarized light microscope with liquid crystal universal compensator and circular polarizer (the LC-PolScope) for recording images, which are independent of the orientation of birefringent objects. Separate images show the retardance and the slow axis azimuth distributions of the in-plane birefringence of the focused region in the specimen. However the measured (apparent) retardance still depends on the angle between the crystal optic axis and the axis of the illuminating beam of light. If the illuminating beam is close to parallel to the optic axis the measured retardance value decreases dramatically and becomes zero when the two axes are parallel. The description of birefringent objects oriented in 3-dimensional space requires the introduction of two additional parameters: the principal retardance and the inclination angle. Together with the azimuth angle they completely characterize the birefringence properties of a specimen, assuming the specimen has a uniaxial optical indicatrix. We devised a new technique for measuring the three birefringence parameters without moving the specimen. For exploring the out-of-plane birefringence the new instrument which is based on the LC-PolScope technique contains an additional spatial light modulator, implemented here as a liquid crystal mask. The mask is located in the aperture plane of the condenser lens. Partial occlusion of the condenser aperture changes the direction of the central ray of the cone of light converging on the specimen. So we can obtain the retardance and azimuth images using different sets of illumination rays. For experimental verification we used a biological object called an aster. An aster consists of nearly parallel arrays of microtubules, a stiff biopolymer, radiating from a common organizing center called a centrosome. The object is spherically symmetric, and its 3 dimensional distribution of birefringence orientation can be predicted. Experimental results have shown the developed polarizing microscope can successfully be used for imaging and measuring three-dimensional orientation of birefringent objects.
Date: November 07, 2007 (Wednesday)
Time: 10.30 am
Venue: E3A, Level-7 Pantry area.
I am going to discuss following interesting paper that talks about measuring 3D distribution of birefringence in the sample. It is interesting in its own right as a basic technique and seems to be a good method of visualizing microtubules during mitosis without any label .
Mapping polymer birefringence in three-dimensions using a polarizing microscope with oblique illumination
Michael Shribak and Rudolf Oldenbourg
Marine Biological Laboratory, Woods Hole, MA 02543, USA
ABSTRACT
We have been developing a polarized light microscope with liquid crystal universal compensator and circular polarizer (the LC-PolScope) for recording images, which are independent of the orientation of birefringent objects. Separate images show the retardance and the slow axis azimuth distributions of the in-plane birefringence of the focused region in the specimen. However the measured (apparent) retardance still depends on the angle between the crystal optic axis and the axis of the illuminating beam of light. If the illuminating beam is close to parallel to the optic axis the measured retardance value decreases dramatically and becomes zero when the two axes are parallel. The description of birefringent objects oriented in 3-dimensional space requires the introduction of two additional parameters: the principal retardance and the inclination angle. Together with the azimuth angle they completely characterize the birefringence properties of a specimen, assuming the specimen has a uniaxial optical indicatrix. We devised a new technique for measuring the three birefringence parameters without moving the specimen. For exploring the out-of-plane birefringence the new instrument which is based on the LC-PolScope technique contains an additional spatial light modulator, implemented here as a liquid crystal mask. The mask is located in the aperture plane of the condenser lens. Partial occlusion of the condenser aperture changes the direction of the central ray of the cone of light converging on the specimen. So we can obtain the retardance and azimuth images using different sets of illumination rays. For experimental verification we used a biological object called an aster. An aster consists of nearly parallel arrays of microtubules, a stiff biopolymer, radiating from a common organizing center called a centrosome. The object is spherically symmetric, and its 3 dimensional distribution of birefringence orientation can be predicted. Experimental results have shown the developed polarizing microscope can successfully be used for imaging and measuring three-dimensional orientation of birefringent objects.
Date: November 07, 2007 (Wednesday)
Time: 10.30 am
Venue: E3A, Level-7 Pantry area.
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