True color is the final frontier in holography on emulsion glass plates. Artist and museums, as well as commercial companies, have been waiting for the day when a hologram can be shown not only in full dimension but also in full color fidelity. At
Englewood High School, that day arrived on February 24, 2010 when students in the Communication Technology program created what is believed to be the FIRST true color RGB laser hologram on an emulsion glass plate ever produced by a high school in the United States and possibly the world.
Led by technology education instructor Bill Pugh and holography consultant Frank DeFreitas, students learned the procedure and set up to produce the true color hologram. In the past, glass plate holograms have been in color, but the color has been simulated color or what is also known as pseudo-color.
The Englewood students’ holograms are true-color, meaning that the hologram was created with lasers providing the three primary light sources of red, green and blue. The holograms contain a three-dimensional image that is so real, the viewer thinks the object is really there, but what they are looking at is a holographic image recorded with lasers and made entirely of light.
The students worked in teams and began several months of preparation before DeFreitas’s arrival. During this time, students were taught about the three lasers, optics, beam splitters, frontal mirrors, plate holders, exposure ratios and emulsion glass plates to be used in the color hologram project.
Their lessons also included studying the different types and wavelengths of the three lasers that would be used, and they were shown how the light would react when combined. DeFreitas was in contact with Pugh and his classes throughout this prep period, and had shipped down the green laser to be coupled with Englewood’s HeNe red laser. Students then began the task of combining the red and green laser beam together into one beam.
DeFreitas arrived at the school for a three-day workshop, which included a multi-hologram display with a combination of student and professionally made holograms for the students to view. DeFreitas brought the blue laser to be introduced to the already red and green lasers that were set up on the holography table in Pugh's lab. When all three red, green and blue lasers were aligned and balanced properly, the result was a pure white beam of light.
Combining the lasers was not easy, and required the students to have a lot of patience and go through many trials and errors. The three beams not only have to be combined, but they have to stay combined over a seven-foot distance and could not separate. The power of each laser was different and needed to be calibrated to create the same power of light, which was accomplished by the use of lens, mirrors and many beam splitters.
The full color glass plate holograms created in the Englewood laser lab shows all the colors of M&Ms. However, like many first-time experimental holograms, this one is not as bright as the students had hoped, but bright enough to show the objects and their colors.
Another hologram was shot after a few adjustments. The students were encouraged to see the brightness of the second hologram from the earlier hologram, but realized that they had more work ahead of them. DeFreitas reminded them of Englewood’s very early “regular” one-laser holograms, and how far they had come by experimenting, improving and passing their successes onto others. Now, it will be for other classes in the future to build upon the foundation that these students have provided.
These first true color holograms of satisfactory quality will springboard to further full color improvements in the future. The hands-on experience of holography has given the students the practical application of their lessons learned in academic classes, in areas such as physics, math, chemistry and research. With the work of these students, all eyes in holography have been turned to Englewood High School’s holography program.
Mr. Pugh, Mr. DeFreitas, and the Communication Technology students would like to thank the support given to the holography program from the Duval County Career/Technical Education Department and Englewood High School. Without this support, students would not be given the opportunity of expanding their higher level of learning with a project such as this.
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