A low quality fiberscope observing the inside of an antique clock mechanism. Note how individual fibers are discernable, as each fiber only relays one part of the image.

A fiberscope is a flexible optical fiber bundle with a lens on one end and an eyepiece or camera on the other. It is used to examine and inspect small, difficult-to-reach places such as the insides of machines, locks, and the human body.


Guiding of light by refraction, the principle that makes fiber optics possible, was first demonstrated by Daniel Colladon and Jacques Babinet in Paris in the early 1840s. Then in 1930, Heinrich Lamm, a German medical student, became the first person to put together a bundle of optical fibers to carry an image. These discoveries led to the invention of endoscopes and fiberscopes.[1] In the 1960s the endoscope was upgraded with glass fiber, a flexible material that allowed light to transmit, even when bent. While this provided users with the capability of real-time observation, it did not provide them with the ability to take photographs. In 1964 the fiberscope, the first gastro camera, was invented. It was the first time an endoscope had a camera that could take pictures. This innovation led to more careful observations, and more accurate diagnoses.[2]


Fiberscopes work by utilizing the science of fiber-optic bundles, which consist of numerous fiber-optic cables. Fiber-optic cables are made of optically pure glass and are as thin as a human’s hair. The three main components of a fiber-optic cable are:

The following are the two different types of fiber-optic bundles in a fiberscope:

Total internal reflection

Fiber-optic cables use total internal reflection to carry information. When light travels from one medium to another it is refracted. If the light is traveling from a less dense medium to a dense medium it is refracted away from the normal. The opposite applies if the light is traveling from a dense medium to a less dense medium. In optic cables, light travels through the dense glass core (high refractive index) by constantly reflecting from the less dense cladding (lower refractive index). This happens because the surface of the core acts like a perfect mirror and the angle of the light is always larger than the critical angle.[4]


Medical applications

Fiberscopes are used in the medical field as a tool to help doctors and surgeons examine problems in a patient’s body without having to make large incisions. This procedure is called an endoscopy. Doctors use this when they suspect that a patient’s organ is infected, damaged, or cancerous. There are numerous types based on the area of the body being examined. They include:

Although any medical technique has its potential risks, using a fiberscope for endoscopy has a very low risk of causing infection and blood loss.

Other applications

Locksmiths use fiberscopes to check the position of pins. Technicians and inspectors use fiberscopes to look at the inside of machines without having to disassemble them. Fiberscopes can also be used in a military or police application to check beneath doors or around corners, or otherwise perform surveillance or reconnaissance.

In popular media

See also


  1. ^ Bellis, Mary. "The Birth of Fiber Optics". Archived from the original on 12 July 2012.
  2. ^ "VOL. 3 Birth of Fiberscopes". Archived from the original on 13 November 2011. Retrieved 12 November 2014.
  3. ^ Freudenrich, Craig (6 March 2001). "How Fiber Optics Work".
  4. ^ "Total Internal Reflection". Retrieved 12 November 2014.
  5. ^ "Industrial Fiberscope" (PDF). Archived from the original (PDF) on 27 November 2014. Retrieved 13 November 2014.