Fiber Optic Cable and Optical Fiber Conclusion
This lab is the second part of the fiber optic labs. This lab allowed me to describe how
light propagates through an optical fiber. I also learned how light attenuated due to
numerical aperture, fiber, area, connector, and bending losses. The first part of this lab
was basically finding angle of reflection and refraction. This is how light bends when it
hits a different medium. The second part of the lab it explains how the attenuation occurs
when light travels through a fiber optic cable. This part shows how when light travels
toward the cladding, the gradual lowering of the refraction index bends the light and this
increases the angle of incidence. When the angle of incident becomes large enough, the
light reflects back towards the center. Sometimes when the manufacturing is not perfect,
it will cause light to scatter. Imperfections in the core to cladding interface are called
microbends. Microbends cause additional scattering losses. Scattering losses decrease as
wavelength increases. Fiber attenuation is due to light scattering and absorption.
Attenuation can be determined by comparing differing lengths of identical fiber. Fiber
losses are specified in dB/km. Attenuation increases by wavelength, affected by
wavelength and affected by the fiber material. The last part of the lab is polishing the
fiber. It can help identify losses in optical connections using visual inspection and power
measurements. I followed the instructions to polish the fiber and got a pretty good result.
The light travels a lot better through polished fiber. The very last part of the lab wanted
us to connect fibers together. However, there was insufficient hardware that hindered us
so we weren’t able to complete the last part.