strambc
commented
3 years ago RELEVANT INFORMATION Attenuation in fiber optics, also known as transmission loss, is the reduction in the intensity of the light beam (or signal) with respect to distance traveled through a transmission medium. Attenuation coefficients in fiber optics usually use units of dB/km through the medium due to the relatively high quality of transparency of modern optical transmission media. The medium is typically a fiber of silica glass that confines the incident light beam to the inside.
Attenuation (dB) = 10 x log10 (Input Intensity (W)/Output intensity (W)) The decibel (dB) is used to express the ratio of one power value to another, on a logarithmic scale.
Example:
- In the case the material of a given fiber has 30 dB/km attenuation, if the actual fiber is 2m long one can calculate the effective attenuation of the fiber as follows: -- 30/1000m = A-eff/2m -- A-eff= 0.06 dB
- Then, assuming the input illumination power is 100, the transmitted (output) illumination power (x) can be calculated as follows:
- A-eff=10.log10 (100/x)
- x = 100/10^(A-eff/10)
- Finally, the transmittance can be calculated as follows: -- T% = 100 - x
Propose a change to existing metadata elements or fields/values, e.g. to identify a problem.
Element name(s): Lens, Mirror, Filter, Dichroic, LightSourceCoupling/LightGuide, Prism
Justification for the addition (brief and compelling): There appear to be a general discrepancy between the use of Make sure the use of Transmittance vs. Attenuation vs. AttenuationCoefficient is consistent across the model
Full description of the proposed addition (enough detail to implement): Make sure the use of Transmittance vs. Attenuation vs. AttenuationCoefficient is consistent across the model