| Today low loss fiber optic systems offer almost | | | | only carrier in these systems is light there is no |
| unlimited bandwidth and unique advantages over all | | | | danger of electrical shock to the personnel |
| previously developed transmission media. The | | | | repairing broken fibers. |
| basic optical transmitters convert electrical signals | | | | Main function of fiber optic light source is to |
| into modulated light for transmission over an | | | | enable the light pulses move in fiber and works on |
| optical fiber. The most common devices used as | | | | the principle of total internal reflection, which |
| the light source in optical transmitters are light | | | | states that when the angle of incidence exceeds |
| emitting diode. Fiber optic light source make a | | | | a critical value light cannot get out of the glass |
| good use of this, as light emitting diodes have | | | | instead it bounces back. The fiber optic light |
| relatively large emitting areas and used for | | | | source works on this principle as it enables to |
| moderate distances. Fiber optic light source prove | | | | transmit information down fiber lines in the form |
| to be economical. | | | | of light pulses. |
| A fiber optic light source device is mounted on a | | | | There are many kinds of sources available that |
| package that enables optical fiber to couple as | | | | act as a fiber optic light source. A fiber optic light |
| much light as possible into the fiber. In some | | | | source usually comes in a rugged splash proof |
| cases a tiny spherical lens is also fitted to collect | | | | case and has single switch operation. A fiber optic |
| and focus each possible light onto the fiber. LED's | | | | light source has combination source for showing |
| i.e. light emitting diode and light diodes operate in | | | | on or low battery. A single battery in a fiber optic |
| infrared portion of electromagnetic spectrum. | | | | light source supplies over 40 hours of operation in |
| Their operating wavelengths are chosen according | | | | case of stable temperature compensated LED |
| to the need. Fiber optic light source is reliable and | | | | with 850 nm and/or 1300 nm fiber optic light |
| the most common wavelengths used by fiber | | | | source supply. They provide 40 dB measurement |
| optic light source today are 850 to 1300 | | | | ranges when used with Fiber OWL or Micro OWL. |
| nanometers or in some cases even 1500 | | | | There are also laser models available in this |
| nanometers. Both LED's and LD's (light diodes) are | | | | category. |
| available in three wavelengths. | | | | In case of 1310 nm or 1550 nm output supplies |
| There are two methods through which light can | | | | which are temperature compensated, a single |
| be coupled into the fiber optic light source. One is | | | | battery provides over 60 hours of operation. It |
| by pig-tailing and the other is placing the fiber's tip | | | | provides 50 dB measurement range when used |
| in very close proximity to an LED or LD. Since the | | | | with Fiber OWL or Micro OWL. |