Optical fiber characterization and transmission

Item Code: SK177

Working and Principle :

In over fiber-optic system, we use multi-mode optical fibers for the transmission of optical signals. Diode laser is used as light source, whether the system transmits digital or analogue signals. Laser fiber coupler is used to couple light from laser to fiber input end efficiently. There are mounts to hold input and output ends of the fiber firmly. Compute numerical aperture from the formula:
... NA= sinƟmax = W/ (4L2 +W2)½
The relationship between an laser optical output Po and the laser forward current If is given by
Po=KIf (over a limited range)




  • Separate Transmitter and Receiver modules
  • Multi-mode fiber cable 2m and 5m length.
  • LED light source with 660nm wavelength.
  • Saddle can hold rod from 8 to 15mm.
  • Heavy, rigid and stable Triangular Optical bench (made of Al extrusion).
  • Height and level adjustment screws (made of SS)

  • To measure numerical aperture of multi-mode fibers.
  • To study the characteristic of 650nm diode laser.
  • To study the characteristic of fiber optics photodetector.
  • Measurement of splicing losses, bending losses and air gap losses in multi-mode fibers.
  • To determine the refractive index of transparent solids
  • Fiber optics cable : PMMA (core), Fluorinated polymer (cladding), Step index structure, 960 micron/1000micron (core/cladding dia.) 1.492 (core refractive index), 1.405 to 1.417 (cladding refractive index), 0.5 (numeric aperturem (typical), 55 to 60 (acceptance angle) 0.3dB/m (attenuation (660nm), 2.2 mm OD polythene (jacket material)
  • Source (LED) : 660 & 850nm, SMA connector, power range 0 to 55 dbm, power supply +5V DC size 32 x 19 x 14mm
  • Detector : Wavelength 660nm, SMA connector, optical power 50m W (peak), power supply +5V DC, band width dc to 20 kHz (min)
  • 1 Two – meter & 5 meter PMMA Fiber (Multimode)
  • 1 Two – meter SPMA Fiber (Multimode)
  • 1 In -Line SMA Adaptor
  • 1 Mandrel with rod
  • 1 NA measurement JIG
  • 1 Optical bench triangular
  • 1 Digital Micro volt metre and 1 Digital Multimeter
  • 1 Fixed slider
  • 2 Transversal slider
  • 1 Transmittor & Receiver module
  • 1 Circular screen with angle measurement
  • 1 Transparent solid
  • 4 Flexible gun type lead (Yellow – 50cm)
  • 2 Flexible lead pair(Red & Black – 50cm)
  • 2 Adaptor 9V, 1 Amp DC
  • Fiber communication.
  • Numerical aperture.
  • Photo detector.
  • Photo transistor.
  • Optical losses.
  • Conversion efficiency.
  • Intensity modulation system.
  • Coefficient of attenuation.
  • Refractive index.
  • Characteristics of diode laser