公开(公告)号：US20220364912A1

公开(公告)日：2022-11-17

申请号：US17767185

申请日：2020-10-08

Applicant: FFE Limited

Inventor： Oliver Burstall ,  Steve Revill

IPC: G01J1/04 ,  G01N21/53 ,  G08B13/184

Abstract: Abeam detector apparatus (1) comprising: beam emitter apparatus (2); reflector apparatus (3), locatable across a volume to be monitored; and beam receiver apparatus (4). The beam emitter apparatus (2) is capable of creating a first linearly polarised beam of light of first linear polarisation and directing said first linearly polarised beam of light towards the reflector apparatus. The reflector apparatus (3) is capable of either: receiving the first linearly polarised beam of light and modifying such light into a beam having circular polarisation, elliptical polarisation or being unpolarised, and reflecting said circularly polarised, elliptically polarised or unpolarised beam of light towards the beam receiver apparatus; OR receiving the first linearly polarised beam of light and reflecting such light towards the beam receiver, and modifying such light into a beam having circular polarisation, elliptical polarisation or being unpolarised. The beam receiver apparatus (4) is capable of receiving said circularly polarised, elliptically polarised or unpolarised light and creating therefrom a second linearly polarised beam of light, in which the first and second linearly polarised beams of light have different polarisation.