Archive of Holoworld:HoloWorld went online on Tue, 04 Dec 1993 21:29:02 GMT (as the Internet Webseum of Holography) during the era of dial-up 14.4 modems and NCSA Mosaic browsers. Chronologically archived copies of the entire HoloWorld web site can be found at the Internet Archive Project. It had been archived 618 times between 5 Nov, 1996 and 7 Dec, 2017. As such, it preceded the Internet Archive itself by nearly three years: | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 |
"Learning is more interesting when you are doing something hardly anyone else in the world is doing."
Hello, my name is Frank DeFreitas ...(above photo): Student members of one of my many "H.I.T. Squad" classes over the years (Holographic Investigative Technologies).
Now retired (as of 2017), I have had a long and very rewarding 35 years working within the Nobel prize- winning fields of lasers and holography.
But I'm not finished yet!!!
My life-long passion has been to bring lasers and holography out of the professional laboratories and into the hands of students, educators, amateurs and enthusiasts. Utilizing the information that I wrote for my Make Magazine Issue #25 DIY laser holography article, I return once again with a very unique and educational-rich application: Forensic Laser Holography.
"3D laser holograms will provide the forensic investigator an unprecedented opportunity to extract visual information, far beyond the limitations of traditional photography." -- Frank DeFreitas
YOU Can Become a FORENSIC LASER HOLOGRAPHER...
Are you ready to become a "laser investigator?". If you have already made simple, single-beam reflection holograms at home or school, like in my Make Magazine article, you are already 90% there. The remaining 10% of necessary tasks consist of the proper recording and reconstruction geometry to match your microscope (depending on the stereo microscope that you are going to use).
(above photo): This *looks* like a spent bullet shell is being examined under this microscope. In reality, there is no bullet shell there at all … it is a 3D laser holographic image. The bullet shell was recorded in a laser holography laboratory. In all respects, it visually acts as if the original shell were there.
(above photo): The "real" bullet shell (left) cannot be distinguished from the holographic image of it (right). The hologram is just as dimensional as the actual object.
(above photo): 3D holographic image of the spent bullet shell, as seen through the microscope. If the examiner utilizes a 3D stereoscopic microscope, the 3D hologram will provide a true, spatial, 3D examination of the object.
There are many methods in which holography has made inroads into microscopy. After all, the original intent of inventor Dr. Dennis Gabor was the improvement of the electron microscope. There are also many current-day methods which are being touted as "digital holographic microscopy" and so on. Also remember, lenses can be made into holograms as well … and they will continue to function as if they were the original lenses! Therefore, it is possible to "encode" the enlarging optics into the hologram, eliminating the need for the optics contained within a microscope. The hologram becomes both the recording of the object, and the microscope used to view it -- both at the same time.
"Thousands of holograms could go to thousands of researchers around the world." -- Frank DeFreitas
Holograms can contain information about the object that may not be of any importance at first examination, but which become of vital importance later in an investigation. 3D laser holograms will provide the forensic investigator an unprecedented opportunity to extract visual information far beyond the limitations of traditional forensic photography.
(above photo): An early (1999) forensic laser holography project was receiving a few test bullets from a well-known JFK assassination investigator. I told him that I could make 3D hologram duplicates of the bullet results ... as if the test bullet itself was being exactly duplicated. You'll have to excuse the lack of photo quality, these photographs of the hologram were taken with the very first consumer digital camera: the Kodak DC20.
Holograms have a quality that is not shared by ANY other 3D imaging media: SPATIAL depth of field. This means that the field depth is reconstructed within a VOLUME of space. The empty space between objects actually exists. Details that are out of focus can be brought in to focus ... just as if the physical 3D object(s) were being examined. And, remember, that this 3D VOLUME of SPACE (and all objects recorded within it) is stored within a *2D* media.
(above photo): Proof-of-concept: Holograms can be made of the Shroud of Turin fabric, duplicated, then sent for 3D visual examination around the world … without ever touching the actual Shroud.
Proof-of-concept: Shroud of Turin. Regardless of what one believes about the world-famous Shroud of Turin, the fact remains that it is the most scientifically studied artifact in world history. Currently, the Shroud is a limited resource for scientists in that access for physical examination is heavily restricted (it is currently off-limits entirely). Visual examination relies on traditional photographic documentation. I propose that the non-destructive recording of laser 3D holograms of linen fibers could provide an opportunity to break this long-held scientific and technological investigative barrier. Forensic laser holography would provide a non-destructive way for investigators to study the Shroud in true three-dimensional fidelity. While the "real" Shroud remains safe and secure, the holograms would remain readily available long after the Shroud has been returned to controlled storage.
"Laser holograms can take the place of real objects under the 3D stereo microscope. They even exhibit true depth of field!" -- Frank DeFreitas
(above photo): In the late 1980's, I recorded this human skull hologram for the University of Pennsylvania Museum of Archaeology and Anthropology in Philadelphia. And thus began my interest in forensic / historical applications of holography. It is believed to be of a British Revolutionary War Soldier killed during the Battle of Germantown in the 1700's.
Also remember that holograms are recorded onto thin film. This means that objects too large for many microscopes can be recorded and viewed -- since the object is not "there" anymore. Only the thin film containing the 3D laser holographic image of the object needs to go under the microscope.
(above photo): The above photo shows an example of making a three dimensional hologram of soil sample, and what that soil sample looks like under the microscope. It acts exactly the same as the soil physically being there again. When viewed under a stereo microscope, the soil become 3-dimensional with full depth and parallax.
-- Frank DeFreitas
Student Resources and Links:
Lasers, Holography and Photonics Primer: Here is a great PDF student study guide that you can read and / or download to help with your understanding of lasers, optics, and holography. It also contains history and bios of some of the early researchers in the field. You may use it for homework assignments. Please give credit to holoworld.