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RP Fiber Power – Simulation and Design Software for Fiber Optics, Amplifiers and Fiber Lasers

Key Features

The key features of the latest version (V8) are:

mode patterns

Mode Solver

The software contains an efficient mode solver, which can calculate the amplitude profiles, effective mode areas, cut-off wavelengths, propagation constants, group velocities and chromatic dispersion of all guided fiber modes from a given radially symmetric refractive index profile. This is very useful both for models with passive and active fibers – even for cases with several hundred modes.

Example cases show how one can analyze the modes of a graded-index fiber, or simulate launching light into a multimode fiber.

See our demo video for using the mode solver.

fiber coupler

Numerical Beam Propagation

Since V5, RP Fiber Power can propagate optical fields with arbitrary complex amplitude distributions through fibers or other waveguides with arbitrary weakly guiding refractive index profiles. The fiber may be bent (with arbitrarily varying bend radius), tapered, exhibit random index variations, etc. – there is a huge range of opportunities for a wide range of research topics.

Example cases show studies concerning the evolution of light for a misaligned input beam, pump absorption in double-clad fibers, and the behavior of light in a tapered region of a fiber.

See our demo video for numerical beam propagation.

A convenient interactive beam profile viewer allows you easy inspection of any calculated beam profiles.

energy levels

Laser-active Ions

Normally, one works with the standard gain model which is relatively simple. For more complicated laser ions, however, it is possible for the user to freely define energy level schemes of laser-active ions and a great variety of processes inducing transitions between these levels. Therefore, the software is applicable to any conceivable laser ions (Nd3+, Yb3+, Er3+, Tm3+, Pr3+, …) and pumping schemes. It can even handle cases with different ion species combined (e.g. Yb3+ and Er3+) or with complicated quenching processes. It can also describe upcon­version lasers of various kinds.

optical channels

Multiple Pump Waves, Signals, and ASE

You can define a large number of so-called optical channels for pump waves, signals and amplified spontaneous emission (ASE). Each channel may represent either a single propagation mode or some (possibly large) collection of modes. You can freely define its transverse intensity distribution, or simply use the mode intensity distributions from calculated fiber modes. The software is also suitable for modeling devices based on double-clad fibers. For lasers, both linear and ring configurations are possible.

The software can calculate the distribution of all optical powers and excitation densities with an amazing speed and very high reliability. The sophisticated algorithms allow that even in complicated cases. (With other software, you might easily have much longer computation times and convergence issues in complicated situations.)

dynamic simulation

Dynamic Simulations

The software can also simulate the temporal evolution of optical powers and excitation densities. For example, it can simulate the distortion of an optical pulse by gain saturation during amplification in a fiber amplifier (see the figure). It can also simulate the pulse generation in a Q-switched fiber laser or even a bulk laser. Dynamic simulations are possible both with propagation only of optical powers and with propagation of full beam profiles.

All this can be done with uttermost flexibility. For example, you can freely define the time dependencies of the powers of pump and input signal waves, and illustrate the results as you like: display how the values evolve within a pulse, show how the pulse parameters evolve for multiple pulses, etc.

ultrashort pulse

Ultrashort Pulse Propagation

The software can simulate the propagation of ultrashort pulses in passive and active fiber devices, and also in other components such as spectral filters, manually or automatically optimized dispersive compressors, prism pairs and grating pairs, modulators and saturable absorbers. One may thus model not only single-pass amplification in a fiber amplifier or data transmission in a telecom fiber cable, but also the pulse evolution in mode-locked fiber lasers, chirped-pulse amplifier systems, regenerative amplifiers and fiber interferometers. The interactive pulse display window allows one to conveniently inspect all details of the pulses.

The temporal and spectral pulse properties can evolve in a fiber under the influence of arbitrary chromatic dispersion (which may be obtained from the mode solver), the Kerr nonlinearity, stimulated Raman scattering (SRS) and amplifier gain (including gain saturation). Self-steepening can be included; even supercontinuum generation can be simulated. A refined numerical algorithm with automatic step size control ensures a high accuracy combined with high speed.

ytterbium transition cross-sections

Fiber Data

RP Fiber Power comes with a substantial number of fiber data sets, containing spectroscopic data for various laser-active glasses doped with ytterbium, erbium, thulium, etc., and partially also waveguide parameters. Some data sets contain data from the scientific literature, others are obtained from fiber manufacturers cooperating with RP Photonics. In addition, you can easily integrate any own fiber data in the software.

You can also use the technical support in order to get additional fiber data files, made from data which are supplied by the user or the manufacturer.

regenerative amplifier

Use for Bulk Lasers and Amplifiers

You may use RP Fiber Power even for bulk lasers, as long as the beam radii are approximately constant within the laser crystal. This condition is well fulfilled for many end-pumped lasers. For example, you may simulate a Q-switched Nd:YAG laser, investigating pulse build-up with continuous or pulsed pumping, multiple transverse modes, the influence of quenching processes, etc. Also, you can investigate more complex devices such as regenerative amplifiers.

Power Forms

Simple Use and Uttermost Flexibility

The quality of the user interface is an essential aspect. A key goal must be to ensure easy use but also provide high flexibility to make the software applicable to a wide range of cases.

RP Photonics has developed cute solutions for combining such qualities:

  • The new RP Fiber Power Power Forms make it easy e.g. to configure simulation models even for complex multi-stage fiber amplifier systems and the required diagrams:
    • Out of the box, they provide substantial flexibility to treat a wide range of cases – without any need for scripting.
    • Various special demands, which would normally go beyond of what you can do with a form, can be met by entering a little script code into a form. For example, with only few code lines entered, you can get a pump power automatically calculated such as to obtain the needed signal power.
    • If you need more flexibility, you can make tailored versions of those forms – as required, with our diligent help. For example, you can have additional input and output fields or new diagrams.
  • If your simulations are completely out of the range of the existing Power Forms, you can make custom forms which are completely tailored to your case – of course, again with help from us. These forms utilize our powerful script language.
  • It is, of course, also possible to write scripts without a form.
  • Since RP Fiber Power V7, there are very nice additional features to support you in the development of scripts – in particular, syntax highlighting in the editors, parameter help, automatic code reformatting and the debugger.
interactive online help

High Quality Documentation

For serious modeling work, you need a high quality product with comprehensive documentation. RP Fiber Power comes with a very detailed PDF manual, explaining not only the handling of the software and the details of the script language, but also what kind of physical model is used, what are the underlying assumptions, etc. In addition, you get all this information in the form of a convenient context-sensitive online help system.

Also, there are over 40 case studies which illustrate many aspects of the possible simulations.

Technical Support and Consultancy


The license fee always contains some number of hours for technical support. The support is done by Dr. Rüdiger Paschotta and Dr. Gareth Moore, the developers of the software. They will give you high-quality technical consultancy on fiber devices even on scientific and technical issues going far beyond purely software-related questions.

The software runs under Windows 11 or older versions. Due to the efficient implementation, the requirements on the PC are generally moderate; only in special cases, it is advantageous to have a fast CPU and a large main memory.

Maybe you want to download the RP Fiber Power PDF brochure with 39 pages.

Go for the Best Available Tool!

No matter whether you are developing fiber laser products in industry or doing scientific research – for being successful and competitive, it is essential that you have the best available tool and support to get your work done in the most productive and efficient manner. Don't waste your time and other valuable resources by trying around with insufficient means.

If you have any further questions or need a quotation: