Patent ID: 11874227
Assignee: THE UNIVERSITY OF DURHAM
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. An apparatus according to claim 1, wherein said vapour of atoms comprises atoms of a first species and atoms of a second species, wherein respective frequencies of said one or more laser beams and said imaging beam are such that at least some of said atoms of said first species, when subjected to radiation of both said one or more laser beams and said imaging beam, are excited to said final excited state which decays to said lower energy state by emission of said optical fluorescence; the apparatus further comprising:
one or more second laser sources for generating one or more second laser beams propagating through said cell, said one or more second laser beams defining a second sensing region in said cell;
one or more second microwave or terahertz sources for generating a second imaging beam for illuminating the object receiving area, said second imaging beam comprising microwave or tera hertz radiation;
wherein said imaging system is arranged for focusing the second imaging beam to form, in use, a second image of said object at said second sensing region in said cell;
wherein respective frequencies of said one or more second laser beams and said second imaging beam are such that at least some of said atoms of said second species of atom, when subjected to radiation of both said one or more second laser beams and said second imaging beam, are excited to a final excited state which decays to a lower energy state by emission of optical fluorescence.