1930: Heinrich Lamm, a medical student, assembles first bundle of transparent fibers to carry an image (of an electric lamp filament) in Munich. His effort to file a patent is denied because of Hansell's British patent.
December 1931: Owens-Illinois devises method to mass-produce glass fibers for Fiberglas.
1937: Armand Lamesch of Germany applies for U.S. patent on two-layer glass fiber (non-optical)
1939: Curvlite Sales offers illuminated tongue depressor and dental illuminators made of Lucite, a transparent plastic invented by DuPont.
Circa 1949: Holger Moller Hansen in Denmark and Abraham C. S. Van Heel at the Technical University of Delft begin investigating image transmission through bundles of parallel glass fibers.
April 11, 1951: Holger Moller Hansen applies for a Danish patent on fiber-optic imaging in which he proposes cladding glass or plastic fibers with a transparent low-index material. Patent claim is denied because of Hansell patent.
October 1951: Brian O'Brien (University of Rochester) suggests to Abraham C. S. Van Heel (Technical University of Delft) that applying a transparent cladding would improve transmission of fibers in his imaging bundle.
July 1952: Harold Horace Hopkins applies for a grant from the Royal Society to develop bundles of glass fibers for use as an endoscope at Imperial College of Science and Technology. Hires Narinder S. Kapany as an assistant when he receives grant.
Spring 1953: Hopkins tell Fritz Zernicke his idea of fiber bundles; Zernicke tells van Heel, who decides to publish quickly
June 12, 1953: van Heel publishes first report of clad fiber in Dutch-language weekly De Ingeneur after submitting brief paper to Nature.
January 2, 1954: Hopkins and Kapany and van Heel publish separate papers in Nature. Hopkins and Kapany report imaging bundles of unclad fibers; van Heel reports simple bundles of clad fibers.
1954: Basil Hirschowitz visits Hopkins and Kapany in London from the University of Michigan
September 1954: American Optical hires Will Hicks to implement develop fiber-optic image scramblers, an idea O'Brien proposed to the Central Intelligence Agency
Summer 1955: Kapany completes doctoral thesis on fiber optics under Hopkins, moves to University of Rochester.
Summer 1955: Hirschowitz and C. Wilbur Peters hire undergraduate student Larry Curtiss to work on their fiber-optic endoscope project.
Summer 1956: Curtiss suggests making glass clad fibers by melting a tube onto a rod of higher-index glass
December 8, 1956: Curtiss makes first glass-clad fibers by rod-in-tube method.
February 1957: Hirschowitz is first to test fiber-optic endoscope in a patient.
1957: Image scrambler project ends after Hicks tells CIA the code is easy to break.
1958: Hicks, Paul Kiritsy and Chet Thompson leave American Optical to form Mosaic Fabrications in Southbridge, Mass., the first fiber-optics company.
1958: Alec Reeves begins investigating optical communications at Standard Telecommunication Laboratories
1959: Working with Hicks, American Optical draws fibers so fine they transmit only a single mode of light. Elias Snitzer recognizes the fibers as single-mode waveguides.