MODELLING OF FBG EQUATION Detailed Description

[olusegunalfred]

: The integral of the reflection functions as  Pdet (λ) = ∫▒〖FBG(λ)δλ〗  where FBG(λ) is the total reflection spectrum  FBG(λ) = FBG1(λ) + (1- FBG(λ)) . FBG2(λ)  FBG1(λ) = exp [(-(λ-λ_FBG1 )^2)/(2σ^2  FBG1)]  FBG2(λ) = exp [(-(λ-λ_FBG2 )^2)/(2σ^2  FBG2)]  Please i need to model these equation in LabVIEW

[RavensFan]

What exactly do you mean by "Modelling"?

LabVIEW has math functions in it.  It even as functions to do integrals.

Exactly where are you stuck?

Without specific questions, we aren't going to be able to help you.  Actually, you haven't asked any question in your message at all.

http://www.catb.org/esr/faqs/smart-questions.html#explicit

[CollindeWit]

Hi!

I am Collin de Wit, an Application Engineer at National Instruments. If I understand correctly you are asking to be able to execute that formula in Labview? This is possbile. But to know the right solution for you we need a bit more information as to what you are looking for.

We hope to hear from you to be able to assist you further.

Best regards,

Collin de Wit

[WCR]

Questions about the FBG equation you presented:

Does the "period" or "dot" between (1-FBG1()) and FBG2() represent multiplication?

In your formulas, the quantity FBG1 follows sigma-squared in one place, and the quantity FBG2 follows sigma-squared in another place.  Should this be subscribts for the sigmas, i.e. is there a quantity sigma(subscript FBG1) and another quantity sigma(subscript FBG2)?  This would make sense, since it would mean you have two standard Gaussian functions, each with its own mean and st.dev., which are given by lambda(FBG1), lambda(FBG2), sigma(FBG1), and sigma(FBG2) respectively.

Did you forget to include a "1" after "FBG" on the right hand side of the second equation in your word document?

I assume the answers to the above questions are yes.  The attached VI computes and plots the spectra FBG1, FBG2, and the combined reflectance.  The VI allows the user to set the values of lambda1, lambda2, sigma1, and sigma2.  The VI also allows the user to set the low and high wavelegth limits for evaluating the functions.  It would be a relatively simple matter to add a bit of code to integrate the total reflection spectrum from the low limit to the high limit.  Note that there is a constant, Nsteps, on the block diagram.  This is the number of wavelength steps from the low limit to the high limit. A higher value results in "finer" steps.  A subVI to compute the Gaussian function is also included.

[WCR · Accepted solution]

Screenshot of the VI.