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Legal and Contact Information

Here you can find basic data on RP Photonics AG.

This page serves as an imprint, also for the following social media:

Contact Information

Mail address: RP Photonics AG
Bannhaldenstr. 38
8500 Frauenfeld
Note: We have moved to Switzerland in February 2022! The business is now done by the new Swiss company which we founded there. (The previous German company was: RP Photonics Consulting GmbH, Waldstr. 17, D-78073 Bad Dürrheim, trade register number HRB 706010, Amtsgericht Freiburg i. Br.; it is going to be liquidated.)
Managing director: Dr. Rüdiger Paschotta (also responsible for any content of the website; same postal address as the company)
Telephone: +41 52 720 8000
You can normally reach us 09:00 – 13:00 and 14:00 – 18:00 (central European time). For American customers: we are 6 h ahead of Eastern Time and 9 h ahead of Pacific Time.
Mobile phone: on request

For issues related to the RP Photonics Buyer's Guide, please use the following address:

Incoming e-mails are subject to “gray listing”, a spam filtering technique. In rare cases, where a server sending e-mails is not properly configured, this can cause technical problems; please use the phone in such a case.
You are encouraged to establish secure e-mail exchange for protecting your sensitive information!
In case that you have a problem with replying to digitally signed mails, just mail to our info@ address.
Video chat: We can arrange a contact via Skype,, Teams or Zoom. Please first make an appointment.
FTP: If you need to exchange larger amounts of data (more than a few megabytes) with RP Photonics, an FTP account can be provided.

Please also see our page on privacy.

Various Data

UID (company ID): CHE-141.173.265

Mass Mails from RP Photonics?

Occasionally, large amounts of spam (unwanted mass mails) and phishing attempts are spread which are falsely claiming an e-mail address in the domain as the sender (e-mail spoofing), sometimes even the address of the managing director. (Some “returned” mails then arrive at RP Photonics, so that we see them.) Some of those mails have attachments containing malware, and others try to make you click on a dubious link. Obviously, behind such activities there are criminals who try to gain trust from possible victims by pretending that their mails are from RP Photonics, a reputable source. Some of them are also abusing our company logo and further data, e.g. our telephone number.

We can give some indications for checking whether such mails are from us:

  • Our mails are all properly formatted, written with decent language etc.; the style is very different from what spammers typically use. (Fortunately, spammers normally invest very little time into optimizing such mails; they are mostly targeting easy victims, who do not critically check what to accept.)
  • Of course, RP Photonics is never sending out mails concerning items which are totally unrelated to its business. However, some abuse also happens in the context of photonics.
  • All our mails come from the domain, never e.g. from gmail. Note, however, that the sender address can easily be forged when messages are not digitally signed.
  • Messages from Dr. Paschotta, the founder and managing director of RP Photonics, (but not our newsletter mailings) are always digitally signed; the signature can be validated by your e-mail program and then confirms that a mail is really from Dr. Paschotta.
  • RP Photonics may occasionally ask you to click on a link in our domain (, e.g. to view one of our web pages such as an encyclopedia or blog article, but not on dubious other domains.
  • Since 10/2017, we are using so-called SPF records, with which mail providers can verify that a mail really comes from our domain. If your provider uses that technique, you don't receive such forged mails. Unfortunately, most e-mail providers do not check such records since most sender domains are not (yet) using them.
  • In case of doubt, just forward such an alleged RP Photonics message to us, and we will tell you whether it was from us.

We detected a bigger round of such abuse in June 2017, again in May 2020. Targeted companies are usually in the areas of optics and electronics.

Unfortunately, there is little RP Photonics can do to prevent such e-mails; note that these e-mails are not delivered by the server which processes legitimate RP Photonics mails, but by other servers somewhere in the world on which RP Photonics has no control whatsoever. The same happens to many other companies. Such practices will end only once it is established that each e-mail has to be verified with a digital signature or with an SPF record.

Please do not put our addresses or our domain on any e-mail blacklist. Filtering criteria should be based on e-mail content and possibly other indicators, rather than on the sender or return address, which can unfortunately be forged without any special technical means.