What is normalized frequency of single-mode fiber?
What is normalized frequency of single-mode fiber?
For a step-index fiber, the mode volume is given by V2/2. For single-mode operation, it is required that V < 2.4048, the first root of the Bessel function J0.
How do you calculate the normalized frequency of a fiber?
n2= Refractive Index of Cladding. λ= Wavelength of the light. N.A.= Numerical Aperture of the fiber. Since the V-number of the optical fiber is proportional to the frequency, it is also called as the normalized frequency.
What is LP mode in optical fiber?
linearly polarized (LP) mode: A mode for which the field components in the direction of propagation are small compared to components perpendicular to that direction. Note: The LP description is an approximation that is valid for a weakly guiding optical fiber, including typical telecommunications grade fibers.
What is V number or normalized frequency?
“V Number” The Normalized Frequency Parameter of a fiber, also called the V number, is a useful specification. For example, the number of guided modes in a step index multimode fiber is given by V2/2, and a step index fiber becomes single-mode for a given wavelength when V<2.405.
What is the V number of a fiber give an example?
The V-number is defined as: where V is the normalized frequency (V-number), a is the fiber core radius, and λ is the free space wavelength. Multimode fibers have very large V-numbers; for example, a Ø50 µm core, 0.39 NA multimode fiber at a wavelength of 1.5 µm has a V-number of 40.8.
What is the V number of a fiber?
The V number determines the fraction of the optical power in a certain mode which is confined to the fiber core. For single-mode fibers, that fraction is low for low V values (e.g. below 1), and reaches ≈ 90% near the single-mode cut-off at V ≈ 2.405.
How do you normalize frequency?
You need only divide the frequency in cycles by the number of samples. For example, a frequency of two cycles is divided by 50 samples, resulting in a normalized frequency of f = 1/25 cycles/sample.
Which type of fiber optic cable is most widely used?
A standard multimode fiber-optic cable (the most common brand of fiber-optic cable) uses an optical fiber with a 62.5-micron core and 125-micron cladding diameter. This is commonly designated as 62.5/125 optical fibers.