Guest guest Posted March 29, 2006 Report Share Posted March 29, 2006 A SUBMERSIBLE HOLOGRAPHIC MICROSCOPE. A new device allows scientists to form 3D images of tiny marine organisms at depths as great as 100 m. The device allows the recording of behavioral characteristics of zooplankton and other marine organisms in their natural environment without having to bring specimens to the surface for examination. Scientists at Dalhousie University in Halifax, Canada, used the hologram arrangement originally invented by Denis Gabor: light from a laser is focused on a pinhole that acts as a point source of light if the size of the hole is comparable to the wavelength of light. The spherical waves that emanate from the pinhole illuminate a sample of sea water. Waves scattered by objects in the sea water then combine at the chip of a CCD camera with un-scattered waves (the reference wave) from the pin hole to form a digitized interference pattern or hologram. The digital holograms are then sent to a computer where they are digitally reconstructed with specially developed software to provide images of the objects. The Dalhousie researchers packaged their holography apparatus in such a way that the laser and digital camera parts are in separate watertight containers, while the object plane is left open (see figure at http://www.aip.org/png/2006/255.htm ). One difficulty was to get container windows of optical quality that are thin enough for high resolution imaging but thick enough to resist sea pressure. The new submersible microscope can also record the trajectories of organisms in the sample volume so that movies of the swimming characteristics of micron size marine organisms can easily be produced. Holograms with1024 x 1024 pixels can be recorded at 7 to 10 frames/s. This requires a large bandwidth for data transmission to a surface vessel and was accomplished with water tight Ethernet cables. Imaging volumes can be several cubic centimeters depending on the desired resolution. The Gabor geometry allowed the Dalhousie researchers to design a very simple instrument capable of wavelength limited resolution of marine organisms in their natural environment. Past generations of submersible holographic microscopes had lower resolution, weighed several tons, had to be deployed from large ships, and used high-resolution film as the hologram recording medium. This meant that only a small number of holograms could be recorded. In contrast, the Dalhousie instrument only weighs 20 kg, can be deployed from small boats or even pleasure vessels, and can record thousands of holograms in a few minutes so that the motion of aquatic organisms can be captured in detail. (Jericho et al., Review of Scientific Instruments, upcoming article; contact M.H. Jericho, Dalhousie University, jericho, and also the Universidad Nacional de Columbia) posted for you peter rabbit (bunny is quick!).....bob Quote Link to comment Share on other sites More sharing options...
Guest guest Posted March 30, 2006 Report Share Posted March 30, 2006 Nisargadatta , " Bob N. " <Roberibus111 wrote: > > A SUBMERSIBLE HOLOGRAPHIC MICROSCOPE. A new device allows > scientists to form 3D images of tiny marine organisms at depths as > great as 100 m. The device allows the recording of behavioral > characteristics of zooplankton and other marine organisms in their > natural environment without having to bring specimens to the > surface for examination. Scientists at Dalhousie University in > Halifax, Canada, used the hologram arrangement originally invented > by Denis Gabor: light from a laser is focused on a pinhole that acts > as a point source of light if the size of the hole is comparable to > the wavelength of light. The spherical waves that emanate from the > pinhole illuminate a sample of sea water. Waves scattered by > objects in the sea water then combine at the chip of a CCD camera > with un-scattered waves (the reference wave) from the pin hole to > form a digitized interference pattern or hologram. The digital > holograms are then sent to a computer where they are digitally > reconstructed with specially developed software to provide images of > the objects. The Dalhousie researchers packaged their holography > apparatus in such a way that the laser and digital camera parts are > in separate watertight containers, while the object plane is left > open (see figure at http://www.aip.org/png/2006/255.htm ). One > difficulty was to get container windows of optical quality that are > thin enough for high resolution imaging but thick enough to resist > sea pressure. The new submersible microscope can also record the > trajectories of organisms in the sample volume so that movies of the > swimming characteristics of micron size marine organisms can easily > be produced. Holograms with1024 x 1024 pixels can be recorded at 7 > to 10 frames/s. This requires a large bandwidth for data > transmission to a surface vessel and was accomplished with water > tight Ethernet cables. Imaging volumes can be several cubic > centimeters depending on the desired resolution. The Gabor geometry > allowed the Dalhousie researchers to design a very simple instrument > capable of wavelength limited resolution of marine organisms in > their natural environment. Past generations of submersible > holographic microscopes had lower resolution, weighed several tons, > had to be deployed from large ships, and used high-resolution film > as the hologram recording medium. This meant that only a small > number of holograms could be recorded. In contrast, the Dalhousie > instrument only weighs 20 kg, can be deployed from small boats or > even pleasure vessels, and can record thousands of holograms in a > few minutes so that the motion of aquatic organisms can be captured > in detail. (Jericho et al., Review of Scientific Instruments, > upcoming article; contact M.H. Jericho, Dalhousie University, > jericho, and also the Universidad Nacional de > Columbia) > posted for you peter rabbit (bunny is quick!).....bob > *********** Ouch. Bob the Owl and Peter the Rabbit give Silver the Bear a sore Brain sometimes. " Silver " Quote Link to comment Share on other sites More sharing options...
Guest guest Posted March 30, 2006 Report Share Posted March 30, 2006 Nisargadatta , " s_i_l_v_e_r1069 " <silver- 1069 wrote: > > Nisargadatta , " Bob N. " <Roberibus111@> > wrote: > > > > A SUBMERSIBLE HOLOGRAPHIC MICROSCOPE. A new device allows > > scientists to form 3D images of tiny marine organisms at depths as > > great as 100 m. The device allows the recording of behavioral > > characteristics of zooplankton and other marine organisms in their > > natural environment without having to bring specimens to the > > surface for examination. Scientists at Dalhousie University in > > Halifax, Canada, used the hologram arrangement originally invented > > by Denis Gabor: light from a laser is focused on a pinhole that > acts > > as a point source of light if the size of the hole is comparable to > > the wavelength of light. The spherical waves that emanate from the > > pinhole illuminate a sample of sea water. Waves scattered by > > objects in the sea water then combine at the chip of a CCD camera > > with un-scattered waves (the reference wave) from the pin hole to > > form a digitized interference pattern or hologram. The digital > > holograms are then sent to a computer where they are digitally > > reconstructed with specially developed software to provide images > of > > the objects. The Dalhousie researchers packaged their holography > > apparatus in such a way that the laser and digital camera parts are > > in separate watertight containers, while the object plane is left > > open (see figure at http://www.aip.org/png/2006/255.htm ). One > > difficulty was to get container windows of optical quality that are > > thin enough for high resolution imaging but thick enough to resist > > sea pressure. The new submersible microscope can also record the > > trajectories of organisms in the sample volume so that movies of > the > > swimming characteristics of micron size marine organisms can easily > > be produced. Holograms with1024 x 1024 pixels can be recorded at 7 > > to 10 frames/s. This requires a large bandwidth for data > > transmission to a surface vessel and was accomplished with water > > tight Ethernet cables. Imaging volumes can be several cubic > > centimeters depending on the desired resolution. The Gabor geometry > > allowed the Dalhousie researchers to design a very simple > instrument > > capable of wavelength limited resolution of marine organisms in > > their natural environment. Past generations of submersible > > holographic microscopes had lower resolution, weighed several > tons, > > had to be deployed from large ships, and used high-resolution film > > as the hologram recording medium. This meant that only a small > > number of holograms could be recorded. In contrast, the Dalhousie > > instrument only weighs 20 kg, can be deployed from small boats or > > even pleasure vessels, and can record thousands of holograms in a > > few minutes so that the motion of aquatic organisms can be captured > > in detail. (Jericho et al., Review of Scientific Instruments, > > upcoming article; contact M.H. Jericho, Dalhousie University, > > jericho@, and also the Universidad Nacional de > > Columbia) > > posted for you peter rabbit (bunny is quick!).....bob > > > > *********** > > Ouch. Bob the Owl and Peter the Rabbit give Silver the Bear a sore > Brain sometimes. > > " Silver " > " So they went off together. But wherever they go, and whatever happens to them on the way, in that enchanted place on the top of the Forest a little boy and his Bear will always be playing. " Silver...I have had a romance with Pooh and friends since time immemorial with this little brain of tender heart....good friends are the most precious thing in this veil of tears without pity or self/noself understanding. .......bob Quote Link to comment Share on other sites More sharing options...
Guest guest Posted March 31, 2006 Report Share Posted March 31, 2006 Nisargadatta , " Bob N. " <Roberibus111 wrote: > > Nisargadatta , " s_i_l_v_e_r1069 " <silver- > 1069@> wrote: > > > > Nisargadatta , " Bob N. " <Roberibus111@> > > wrote: > > > > > > A SUBMERSIBLE HOLOGRAPHIC MICROSCOPE. A new device allows > > > scientists to form 3D images of tiny marine organisms at depths as > > > great as 100 m. The device allows the recording of behavioral > > > characteristics of zooplankton and other marine organisms in their > > > natural environment without having to bring specimens to the > > > surface for examination. Scientists at Dalhousie University in > > > Halifax, Canada, used the hologram arrangement originally invented > > > by Denis Gabor: light from a laser is focused on a pinhole that > > acts > > > as a point source of light if the size of the hole is comparable > to > > > the wavelength of light. The spherical waves that emanate from the > > > pinhole illuminate a sample of sea water. Waves scattered by > > > objects in the sea water then combine at the chip of a CCD camera > > > with un-scattered waves (the reference wave) from the pin hole to > > > form a digitized interference pattern or hologram. The digital > > > holograms are then sent to a computer where they are digitally > > > reconstructed with specially developed software to provide images > > of > > > the objects. The Dalhousie researchers packaged their holography > > > apparatus in such a way that the laser and digital camera parts > are > > > in separate watertight containers, while the object plane is left > > > open (see figure at http://www.aip.org/png/2006/255.htm ). One > > > difficulty was to get container windows of optical quality that > are > > > thin enough for high resolution imaging but thick enough to resist > > > sea pressure. The new submersible microscope can also record the > > > trajectories of organisms in the sample volume so that movies of > > the > > > swimming characteristics of micron size marine organisms can > easily > > > be produced. Holograms with1024 x 1024 pixels can be recorded at > 7 > > > to 10 frames/s. This requires a large bandwidth for data > > > transmission to a surface vessel and was accomplished with water > > > tight Ethernet cables. Imaging volumes can be several cubic > > > centimeters depending on the desired resolution. The Gabor > geometry > > > allowed the Dalhousie researchers to design a very simple > > instrument > > > capable of wavelength limited resolution of marine organisms in > > > their natural environment. Past generations of submersible > > > holographic microscopes had lower resolution, weighed several > > tons, > > > had to be deployed from large ships, and used high-resolution film > > > as the hologram recording medium. This meant that only a small > > > number of holograms could be recorded. In contrast, the Dalhousie > > > instrument only weighs 20 kg, can be deployed from small boats or > > > even pleasure vessels, and can record thousands of holograms in a > > > few minutes so that the motion of aquatic organisms can be > captured > > > in detail. (Jericho et al., Review of Scientific Instruments, > > > upcoming article; contact M.H. Jericho, Dalhousie University, > > > jericho@, and also the Universidad Nacional de > > > Columbia) > > > posted for you peter rabbit (bunny is quick!).....bob > > > > > > > *********** > > > > Ouch. Bob the Owl and Peter the Rabbit give Silver the Bear a sore > > Brain sometimes. > > > > " Silver " > > > " So they went off together. But wherever they go, and whatever > happens to them on the way, in that enchanted place on the top of the > Forest a little boy and his Bear will always be playing. " > > Silver...I have had a romance with Pooh and friends since time > immemorial with this little brain of tender heart....good friends are > the most precious thing in this veil of tears without pity or > self/noself understanding. > .......bob > *********** :-) *********** Quote Link to comment Share on other sites More sharing options...
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