EI8075 - Fiber Optics and Laser Instruments

What is the principle of fiber optical communication?

• Frequency modulation

• Population inversion

• Total internal reflection

• Doppler Effect

The ______ serves as a barrier to keep the light within the core, functioning much like a mirrored surface:

• Core

• Cladding

• Coating

• Strengthening Fiber

The light sources used in fiber optics communication are :

• LED’s and Lasers

• Phototransistors

• Xenon lights

• Incandescent

The ________ ray passes through the axis of the fiber core.

• Reflected

• Refracted

• Meridional

• Skew

Light incident on fibers of angles________the acceptance angle do not propagate into the fiber

• Less than

• Greater than

• Equal to

• Less than and equal to

The ratio of the speed of light in air to the speed of light in another medium is called as_________

• Speed factor

• Dielectric constant

• Reflection index

• Refractive index

What is the numerical aperture of the fiber if the angle of acceptance is 16 degree

• 0.50

• 0.36

• 0.20

• 0.27

Calculate the numerical aperture of an optical fiber whose core and cladding are made of materials of refractive index 1.6 and 1.5 respectively.

• 0.55677

• 55.77

• 0.2458

• 0.647852

A step-index fiber has a numerical aperture of 0.26, a core refractive index of 1.5, and a core diameter of 100 micrometers. Calculate the acceptance angle.

• 1.47°

• 15.07°

• 2.18°

• d) 24.15°

A scuba diver is wearing a headlamp and looking up at the surface of the water. If the minimum angle to the vertical resulting in total internal reflection is 25°, what is the index of refraction of the water? index of refraction of air = 1.000

• 2.37

• 1.92

• 1.12

• 0.85