European laws regarding laser display installation may or may not exist, however employment law does. If you ignore any guidance and if something goes wrong and you end up in court, you would have to explain why you were not using the recommended guidance, additionallyyou need to be able to prove/have professional credentials to prove that you competent to evaluate laser show safety. Can't just be some noob hobbyist who wants to scan audiences with lasers based on his or her imagination about lasers.
Why do you want to know German audience scanning laws and regulations since you apparently don't know or even where to look and have not needed to know?
Bottom line will be to prevent anyone from being put in harms way with lasers. There are business laws and other laws related to public laser show displays. Liability insurance requirements and so on in addition to Country laser law regulations. Legal public laser show displays are a whole different world from laser pointers and more complicated than you probably imagine.
IEC 60825 (parts 1 [Equipment classification and requirements], 3 [Guidance for Laser Displays and Shows] and 14 [Safety of Laser Products - user guide] ) cover laser manufacture, specifications and use in Europe. See:
https://webstore.iec.ch/preview/info_iec60825-3%7Bed2.0%7Den.pdf
Generally, you must be at or under MPE, have a scanfail device fitted at a minimum - aside from all the 'usual' things like startup delay, estop, etc and probably (as with most H&S things these days) be able to prove 'competency', both in being able to evaluate if a show is safe, take all reasonable steps to ensure it is if it isn't, and then actually carry out the safe show.
So first steps would probably be to do a safety course, where you'll find out about regulations and laws you'll need to comply with, and how to comply with them.
International Laser Display Association - Audience Scanning
Audience scanning information for ILDA Members
"A: Audience scanning requires a permit or other explicit permission in advance. This permission may be required by the government and/or by the venue operator. Austria, Finland, Germany, Scotland, Sweden, United Kingdom, United States "
Also see ILDA's new web site:
Home | International Laser Display Association
You can call or email ILDA's Executive Director and ask him--he would know about same
Patrick Murphy
ILDA Executive Director
7062 Edgeworth Drive
Orlando Florida 32819, USA
Phone +1 407-797-7654
mail@ilda.com
Talk with and ask these guys--they will know all for sure:
https://www.ds-lasershows.de/?gclid=EAIaIQobChMI7t7Att_i2wIVSbnACh1GoAo0EAMYASAAEgLu1PD_BwE