120 likes | 227 Views
Ankit Kapoor Ashley Jhu Optics Period 6. In fiber optics, a thin, flexible glass tube functions as a transmission line for light from a laser Comparable to a copper wire electrical impulses
E N D
Ankit Kapoor Ashley Jhu Optics Period 6
In fiber optics, a thin, flexible glass tube functions as a transmission line for light from a laser • Comparable to a copper wireelectrical impulses • The purpose of the experiment was to simulate the use of fiber optic cables using a microwave optics system, plastic tube bag and styrene pellets.
thin, transparent and flexible fibers • Transport waves (light, microwaves, etc.) • Carries information • Variation of laser intensity • Immune to electromagnetic interference • Benefit for distances • Main Phenomena Total internal reflection / Snell’s law
n1*sin(θ1) = n2*sin(θ2) (θ2) no solution When n1 >n2, and the angle is within the critical angle range, then it will experience TIR
Index of refraction higher than that of its surroundings • Allows light to travel within cables • PRO: No signal loss • Side note: variation in angle simulation of network within a city (many bends)
Transmitter • Goniometer • Styrene Pellets • Receiver • Tubular Plastic Bags
Place the Transmitter and Receiver directly across from each other • Adjust the Receiver controls for a readable data • After filling a tubular plastic bag with styrene pellets, place one end in the Receiver horn • Remove the plastic bag and turn the Rotatable Goniometer arm until no meter deflection appears • Place the other end in the Transmitter horn
0.6 initial reading • 120 degrees
sin(θc) = nout/nin (modifies Snell's Law for total internal reflection) • The angle between the two arms of the goniometer was 120° when the bag could no longer transmit radiation, so the critical angle is (120° - 90°) = θc = 30°. • nout = nair ~ 1 • nin = nstyrene • nstyrene = nair/sin(30°) = 1/(1/2) = 2
No, because the angles determined by Snell's Law also depend on the wavelength of the radiation. The wavelengths of microwave and optical light are different by several orders of magnitude so the plastic bag filled with styrene pellets would not work with optical light. Additionally, styrene pellets are not considerably transparent to optical light.
Setting of apparatus may be used as a demonstration of how the plane of polarization can be rotated by multiple reflections.