Hi Rick

Your merit function seems properly set up. You are targeting the smallest RMS spot radius. You actually don't need all the boundary operands as only the thickness of 7 is targeted so you could just clear this a bit.

What you could do to make a 1st step is click on Optimize...Quick Adjust:

About the single mode fiber, I think this is correct to use the NA number. I would change the apodization. Usually the NA is given for a gaussian apodization of 1. What does the term apodization mean?. We usually set a higher NA so that the marginal ray contains less energy.

You might also have a look at that article: Should I use POP or Single Mode Coupling for my single-mode fiber coupling system?

Let us know if you have any further questions.

Sandrine

In your syste, an Object Space NA of 0.27 with an Apodization Factor of 4 is equal to an Object Space NA of 0.14 with an Apodization Factor of 1.

An Apodization Factor of 4 means that the intensity of the marginal ray is 1/e^2G = 0.03%.

Sandrine,

Thank you for the helpful information.

I do have another question on the topic of the laser scanner. I want to optimize the position of the moving lens, so the spot is in focus over a broad field. At the moment, I added in my file some configurations via the multi-configuration editor. I don't want to optimize for all, but for each configuration on it's own. How can I do that?

Hi Rick

I have only one configuration in the file you sent. But I probably don't need the file.

When you build your merit function in a multi-configuration system, the default merit function will contain CONF operands. It means that all the operands below a CONF operand will only calculate for a specific configuration. 

For example, if you open the sample file '\Zemax\Samples\Sequential\Zoom systems\Scanning mirror.zmx', I can create a default merit function:

The Merit Function will contain CONF operands. Each spot of each configuration will be optimized separately:

If the variables are in the editor, then the software will try to find a compromise between each configuration. 

If the variables are in the multi-configuration editor, then the software will find the best value in each configuration.

Let me know if that helps and do not hesitate if you have other questions.

Sandrine