shell text (Mayte) Flashcards
what is the Beer-Lambert law
what is cone of acceptance
laser pulses are directed to the fiber line by
means of a _________.
temperature standard deviation will increase with _____ even if the standard deviation of the Raman signals are constant.
a DTS system’s resolution should be stated in terms of fiber length and sampling time.
how is the speed of light in a fiber determined
If the sensitivity is known, the observed temperature
log is made up sum of three components:
the weakest of the backscattered waves, resulting from molecular and atomic vibrations, are the ____Bands
If the velocity of light in the fiber is v, a ____can be opened at some time t to capture that backscattered light.
why do most DTS measurements use multimode fiber
The refractive index of the core is approximately
___% greater than the cladding thereby
assuring the containment of the laser light pulse
within the core.
what does water do to fiber
what are the accuracy and resolution definitions and differences
This light pulse is, in effect, a travelling ____ moving through the fiber line and relaying back temperature information
what is the sampling resolution
red shift is a _____ in wavelength and blue shift is a ______ in wavelength
The Raman signal is the signal used for evaluation of temperature. It is sufficiently strong and has a unique temperature dependence. Its wavelength is also shifted substantially (about ____/Nm) from the main Rayleigh peak,
thereby allowing the dominant Rayleigh and Brillouin peaks to be filtered out
During backscattering, the energized lattice and molecules then give off light having wavelengths at _______ the incident wave.
what is the temperature equation
Resolution can be expressed as ______
of the temperature measurement
what is Snell’s Law
______ laser pulses and smaller time
windows are required to better detect short length high temperature nanomalies.
Laser pulses are directed to the fiber line by
means of a directional coupler. The fiber optic line then passes through a(n) ______ before going into the fiber
what is a graded index
Optical Time Domain Reflectometry (OTDR) is used to access what and with what type of wave
The main backscattered wave is at the wavelength of the
launched wave and is called the ____ peak or band. This is by far the _____ signal returned.
the stokes and antistokes signals signal on the backscatter vary because
what is the equation to determine the lenth of a light pulse
Total internal reflection is based on what law
what is the equation for overstuff
what is Tref and T0
what is optical overstuff
what is the equation for the energy of the returning Ramen backscatter
how long is the lightpulse to measure the fiber
what are the x and y axis for a typical Optical Time Domain Reflectometry (OTDR) graph
For singlemode fiber, longer distances requires ____ and _____
What is the equation to determine window size required to achieve a one meter length resolution along the fiber
what is the equation for overstuff of the fiber caused by its own weight
how is differential loss determined in a DTS wrap back
what are two definitions of spacial resolution
Except for certain special quality control tests, the _______ signal is usually filtered and suppressed.
Those waves associated with the lattice vibrations show up as _____ lines or peaks on the backscatter spectrum.
When that pulse enters the fiber, it is said to be _____
