Modeling in Photonics

How to Get Started with Laser Modeling?

Many people understand well that laser modeling (or more generally, models in photonics) could be extremely valuable for their industrial laser development or for their scientific research, for example. However, they may hesitate to get started because of the concern that it would be too hard to get into this field. Here, we show that it may actually not be that hard; there are some routes which make it fairly easy to profit from laser modeling.

Essentially, you can proceed as follows:

Identify the Technical Aspects of Interest

A first step is to think about what are the most important technical areas for your work as an industrial laser developer or as an scientific researcher, for example:

Do you need to acquire good understanding of laser dynamics, e.g. in the context of Q-switched lasers or pulse amplification?
Do you need to analyze the detailed behavior of laser resonators?
Are you concerned with ultrashort pulse generation, e.g. with mode-locked lasers or with amplifier systems?
Are the detailed processes in some optical components particularly relevant?

It is a good idea to first formulate a number of concrete questions which you would like to address – for example:

What would be the performance of my laser, if all components would work perfectly according to the specifications?
How relevant are gain guiding effects (or unavoidable misalignment, inhomogeneities of pump profiles, etc.) in my bulk laser or amplifier for the performance?
Why can I not obtain shorter pulses from my mode-locked laser? What are the principal limitations? Would it help to change certain details of my system?

Of course, more and more such questions will come up as you get started with modeling. It is important, though, to move on in the right direction.

Who Should Do the Modeling?

You may want to do the required modeling yourself. That way, you will personally acquire a very good understanding of your systems, and you will be able to fully apply the software and the acquired insight to future projects. However, you will have to get into the technical details – mostly the physics and normally to a smaller extent concerning the handling of some software.

In some cases, a colleague in your team may be better positioned to get into this. It can be very sensible that just one or two persons in a team focus on laser modeling, supporting the whole team with the created insight.

If nobody in your team can do that job, that does not imply that you cannot profit from modeling! After all, you can get it done by an external expert. Of course, you want to have an expert who is known to understand the relevant details very well, who has the required software and works with great care. Consider asking Dr. Paschotta from RP Photonics.

Get Computer and Software

If you want to get started yourself, you need a suitable computer and software.

The computer hardware is the smallest of all problems. Most laser models can easily be operated on ordinary personal computers (PCs). Even for quite sophisticated simulations, computation time or memory on a normal PC is not an issue. Where this is different, one may often solve the problem by using a more appropriate kind of model.

Concerning software, find out which supplier is most likely to provide powerful simulation and design software which comes with clear documentation and with competent, helpful technical support. Ideally, you get a software which has been developed by a distinguished technical expert, and where technical support is delivered by the same expert. Also, make sure that you get software which not only gives you an easy start, but also offers enough flexibility to be applied for real work.

You may also consider to develop your own modeling software. This gives you highest flexibility and full control, and you will learn a lot. However, the huge effort of developing a really good and reliable simulation software can often not be justified with the application by a single user. Keep in mind that some quick-and-dirty solution (with a poor user interface, without proper validation and no documentation) can hardly be recommended; it may give misleading results, may be too inconvenient to use and cannot be maintained or even used any more if its creator leaves the group. Also keep in mind that your actual task as an engineer or scientist is probably not developing tools, but delivering results. You are more productive when working with a good simulation and design software, rather than developing such software yourself.

Develop the Technical Expertise

Of course, a certain technical know-how is required when working with laser models; it is not sufficient to have some good software. Note that working with laser models exactly belongs to the very best ways of acquiring a decent understanding – not only concerning quantitative details, but also concerning all the basic physics. Starting with textbook knowledge, you will soon learn more e.g. concerning the limitations of certain concepts or the importance of various effects.

It may well happen that you encounter certain challenges, where your existing know-how is not yet fully sufficient for getting to the solution. Here, high quality technical support coming together with the simulation software can be of crucial importance. Ideally, the software supplier provides technical support not only on handling details of the software, but more generally as a kind of technical consultancy. This is, for example, what RP Photonics offers – note the full name RP Photonics Consulting GmbH.

Just Ask!

Maybe you are not sure whether or not modeling would be sensible in a concrete case. It can be very helpful to discuss this with an experienced expert. Simply contact RP Photonics; you will get honest answers e.g. about which type of model would be suitable and whether modeling is the right approach in your case.