Laser room warning displays, signage, and interlock controls are specified by ANSI Z136.1-2014 for Safe Use of Lasers
Low power systems below class 3B usually only employ a warning sign on the door, whereas higher power systems employ warning lights and access controls that are either Defeatable or Non-defeatable.
Non-defeatable means the laser is interlocked to the entryway and will trip if the door is opened. It is usually set up as depicted in the image below:
Defeatable access controls allow an authorized laser worker to briefly open the door for ingress or egress. In such cases it is imperative that the entryway does not have a possibility of exposure to laser intensity above the maximum permissible exposure level (MPE). An example of a room configured for defeatable access is shown below:
An example layout of some of the modules one might find at a laser table is shown below:
