In 1989, a group of Bell Lab scientists, at Murray Hill, NJ, published a paper about the first side illuminated optical fiber sensor. At the time, this group recognized one of side illumination’s advantages: its very high signal to noise ratio, SNR, if compared to its competing counterpart, axial illumination. Despite this recognition, the early pioneers abandoned their own creation.  Soon afterwards, in 1990, Dr. Claudio Egalon, who may also be counted among the earlier pioneers of this type of optical fiber sensor, started working on this type of device and became the champion of this technique.

Since then, Dr. Egalon has demonstrated several different types of side illuminated optical fiber devices among them:

• A multiple point optical fiber sensor with a fluorescent cladding.
• A multiple point optical fiber sensor with a absorption based cladding.
• A tapered core side illuminated optical fiber sensor with a sensitive cladding.
• A bare core side illuminated optical fiber sensor for fluorescence, absorption, chemiluminescence, reflection, refractive index and other types of measurements.
• An optical fiber coupler.

Among the types of devices demonstrated are:

• Side illuminated active cladding optical fiber sensors:
  • A sensor for chloride ion using a fluorescent cladding.
  • A sensor for relative humidity using an absorption based cladding.
• Side illuminated bare core optical fiber sensors:
  • A sensor for turbidity.
  • A liquid level sensor with a spatial resolution of up to 3 microns .
  • A multiple sample colorimeter.
  • A Planck constant experiment kit.
  • Optical waveguide kits.