I'd rather use the more general beam switching devices.
These are operated by directed light, as opposed to the other large group of cableless communication devices which are operated by radiowaves; the term wireless is kind of reserved for the latter, even though beam/light-based communications are sometimes also referred to as wireless (which they in fact are).
Not sure about the term in English, for two reasons:
1) Light-based communications are subdivided into fibre-optic communications, and optical wireless communications (OWC). The term light switch typically assumes the optical cable type, while beam switch is used in OWC – which is the case here.
However, OWC also includes two types: visible-light communications (VLC) and infrared (IrDA type).
I don't know which type is typically used in sites with explosion hazard; if it is definitely either VLC or IrDA, I guess you could simply use the acronym, eg VLC switches.
2) Beam switch has other usages too. I can think of two right away (there may be more): the low beam/high beam switch in automobiles, and the laser beam modulator in laser devices. Not sure if such usages – particularly the second one – could cause confusion.
Hope this helps.
Note added at 20 hrs (2016-09-30 15:28:17 GMT)
In Bulgarian, the word лъч (= beam, ray) typically implies some kind of directed radiation, mainly light.
The term лъчева система is not a widely used one. It has three typical usages:
1) A system using directed light (be it laser or not). This is the meaning that sounds natural, and is most common.
2) A system of the hub-and-spoke type. In Bulgarian hub is usually център, and spokes are лъчи. However, this sounds a bit awkward, exactly because лъч associates primarily with light.
3) A system that uses some kind of radiation or emission (usually referring to heating systems). This is an incorrect usage because such radiation is not focused or directed, therefore лъчева is inaccurate. An established compromise is the derivative лъчист, as in (системи за) лъчисто отопление.
That said, I don't think anyone would use лъчева система to describe a lighting system.
Moreover that, as far as I see, thе sentence you quoted is part of an official Bulgarian regulation:
IMO лъчева система here refers to the connection between detector components of fire or intrusion alarm systems.
The regulation advises that these should not be of the electrical contact type: not only because cables are always a possible cause of short circuits, but also because the closing of any electrical contact might produce a spark.
Therefore mechanical detectors using electrical contacts should be avoided, and replaced by light-based detector circuits – which are both contactless and cableless (or at least require much less wiring).
These consist of a light emitter and a light receiver, eg a LED and a photosensitive diode. As long as the emitter emits a constant and uninterrupted beam (either visible or infrared light), and the receiver receives it, everything is OK. If, however, a material object passes between the two and interrupts the beam, or if smoke reduces the intensity of the beam received by the receiver, this is an alarm condition.
I believe this is what they had in mind.
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