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RP Photonics
Modeling & Design Software
Technical consulting services on lasers, nonlinear optics, fiber optics etc.
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Powerful simulation and design software.
Make computer models in order to get a comprehensive understanding of your devices!
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powerful tools for efficient laser development and laser science
This page gives you an overview on our software products.
RP Fiber Calculator is a convenient tool for calculations on optical fibers.
RP Fiber Power is an extremely flexible tool for designing and optimizing fiber devices.
RP Resonator is a particularly flexible tool for laser resonator design.
RP ProPulse can simulate the pulse evolution e.g. in mode-locked lasers and sync-pumped OPOs.
RP Coating is a particularly flexible design tool for dielectric multilayer systems.
RP Q-switch can simulate the power evolution in Q-switched lasers.
Most of our software products support a powerful script language, which gives you an extraordinary degree of flexibility.
Here you learn about software license conditions, updates and upgrades, etc.
Competent technical support is a key quality associated with software from RP Photonics.
RP Photonics has distributors in various countries.
The RP Photonics Software News keep you updated on our developments and give the users additional interesting hints.
Here you can make inquiries e.g. concerning technical details, prices and quotations.
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RP Fiber Calculator – Documentation

Here we explain in detail how the RP Fiber Calculator software is used.
Each of the menu items explains one of the tabs.

Launching a Beam

Here you can calculate how a Gaussian laser beam is coupled into a fiber. More precisely, it is calculated what optical powers get into the guided modes of the fiber – using the wavelength and corresponding modes as calculated in the “Guided modes” tab. The fiber end may be misaligned.

RP Fiber Calculator, launching a beam

Input Parameters

The following parameters can be entered:

  • The position offset of the fiber end in x, y and z direction (where z corresponds to the longitudinal direction) against the beam focus position. For example, a positive z value means that the fiber end is placed behind the beam focus, and a positive x value means that the fiber is shifted to the right.
  • The angular orientation error of the fiber end. If this is possible for the x direction, for example, the fiber runs to the right, and a centrally coupled beam initially runs to the left in the fiber.

It is always assumed that the fiber end is cut perpendicular to its axis.

You can also determine whether or not the Fresnel reflection of the (uncoated) fiber end is taken into account, and whether or not modes with very small power are displayed.

Calculated Results

The results are obtained by calculating a complex overlap integral containing the transverse input beam profile and the mode profile.

The calculated results are displayed below when you press the button “Calculate launch efficiency”. For each guided mode of the fiber, the fraction of the incident power which gets into that mode is displayed numerically and graphically. (For modes with non-zero l value, the two possible orientations are listed separately: the one with the sin l φ dependence is indicated with a negative l value.)

The calculation does not consider cladding modes. These, however, will usually exhibit much higher losses, so that after some propagation distance only the power in guided modes remains.

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