SUNDAY, JUNE 24, 2018: Meet me and my Forensic Laser Holography work at the first PHILLY MAKER FAIRE!
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 Technologists). 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 forensic photography." -- Frank DeFreitas
(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 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.
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): 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 concludes about the world-famous Shroud of Turin, the fact remains that it is the most scientifically studied artifact in world history. Currently, it is off-limits to any further study, and might remain that way for some time to come. Forensic laser holography would provide a non-destructive way of investigators examining the very fibers of the cloth itself -- by making 3D holograms and visually examining them under stereoscopic microscopes, anywhere in the world. In full 3-dimensional fidelity. Of course, the object isn't there at all … its a hologram. The "real" object remains safe and secure.
(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.