Lab safety

Lab safety web pages for Physics of Quantum and Nanodevices


BASIC LAB SAFETY: Before ANY work in the lab at all, EVERYBODY must take and get clearance from Johan.

CLEANROOM USE: First contact Johan.

GaAs cleaving: always wear breathing protection! Ask Johan for instructions.

CRYOGENICS: Any handling or use of liquid He or liquid N2: Ask for a complete safety and proper usage training from Martijn. Before that you are not allowed to work with it. Know and understand the dangers.

HIGH MAGNETIC FIELDS (any above 0.5 Tesla): Ask for a complete safety and proper usage training from Caspar. Before that you are not allowed to work with it. Know and understand the dangers.

Ultra-short summary of FND laser safety rules:

When working with lasers in our labs:
1) NEVER where a ring or so around your finger.
2) NEVER where a watch or so around your wrist.
3) NEVER sit on a chair next to the table with eyes at table height.
4) Avoid having shiny objects on your clothing (buttons, belt buckle).
5) Always close your eyes when you bend over and thereby bring your eyes to table height.
6) When a laser is on, at least one of the double doors of the lab entry must be closed. So do not open both at the same time.
7) For now, always pick off a few percent of optical power from the main beam coming out of the laser. Dump all other power in a beam dump right away, and fix the posistions of these items. Never put an apperture or any optics before this pick off point.
8) Be very careful with objects that can fall into a beam (and then scatter light around). Fix all items that are close to powerful beams. Do not ever put pieces of paper and screwdrivers etc. close to powerful beams.
9) When putting new optical components (mirros, lenses, etc.) in a beam line, ALWAYS first block the beam in a safe way, then put in the optical component (at safe position, under safe angle), and then unblock the beam.
10) Keep all beams always parallel to the table surface. Always block any (even weak) reflections that would propagate into the space around the table.
11) For any beam with more power than 100 mW at a fixed position for a long time, build a dark housing or tube around it of black anodized aluminum.
12) Use laser protection goggles as much as possible any time you are aligning laser cavities or beam lines, or installing new optics in a beam line. But understand that these have some finite OD, that may or may not be sufficient for your situation! Calculate the required OD when in doubt, and order more glasses if needed.
13) If in doubt, stop working, and do not do it. Just first ask an experienced user of high-power lasers (Danny or Jakko in our group, or Ben Hesp or Maxim Pshenichnikov of the OCMP group). Always!
14) No guests in the lab when the laser is on, or only with safety goggles on, or when all beams are fully covered.

Before you start with ANY work that involves a laser, you MUST:
1) Study this document on laser safety to teach yourselves! Also browse the links below (or use google) on laser safety information, please tell me which one you find best, or suggest updates.
2) Watch the laser safety video. There is the official RuG video, and a video from Harvard (the one that used to be on The Harvard video is better, and in January 2014 Wesley Browne gave us permission to use the Harvard video instead of the RuG video.

Both the RuG (one *.wmv file) and the Harvard laser safety video (three *.mov movies, total duration is about 45 minutes) are availbale on the Y-drive of the QD team. We also have them for our lab on CD-ROM or USB stick (4 files of about 150 MegaByte each). You can pick them up from Caspar with a USB stick any time.

These are the web links refered to in the video:
to be added.

These are the books that the video refers to:
to be added.

This is the table from the video with damage levels for 0.15 second exposure to your eye (Maximum Permissable Exposures, MPE):
to be added.

Web page with information on local policies is under construction.

All crucial information on LASER safety and handling liquid nitrogen
and liquid helium can be found at the
lab safety web pages of Harvard University Physics (
With here a direct link to web-info on LASER safety.

Laser safety web pages of Indiana University, with ANSI Z136.1 info.

Heidelberg info on laser safety and accidents.
Withe here a specific link on laser accidents.

Try to google your favorite picture of a completely damaged eye from a laser accident……. (I failed to find one that is suited for convincing you to take this very serious)

St-Andrews info on laser safety and accidents.

Also usefuf is this page on liquid nitrogen (

This is a link from