Tapered optical fibres as a probe from MOT characteristics

MOT load & loss• The steady state number of atoms is determined by an equilibriumbetween the loading rate, R load,and the loss rate, R lossof the MOT.• Only atoms with a velocity below the capture velocity, υ c,∼20m/s,can be slowed sufficiently by the laser beam to be trapped.• The rate at which the MOT load, R load, is given by:Rcapute=nRb2/3 4V υ ⎛2 2 ⎟ ⎞cm⎜⎝ kBT⎠3/ 21. Collisions losses between background species in the vacuum system.For our system this can be neglected.2. Collision losses due to background Rb vapour3. Collision losses due to inter-MOT collisions causing and increase in K.E.γ = n σ υ + β( I)lossRbRbRbncloud