Transcript Single Site Addressability in a CO2 Lattice

Lens setup for Rydberg
spatial distribution
Graham Lochead
19/07/10
Outline
• Spatial distribution experiment
• Translation stage
• Lens design
Graham Lochead
19/07/10
Rydberg cloud distribution
V
5sns 1S0
5s5p 1P1
5s2 1S0
Low
density
High
density
Rydberg blockade should alter density profile
Graham Lochead
19/07/10
Ground state distribution
• Measure ground state distribution from MOT floursecence
• Rydberg state scatters too few photons
Graham Lochead
19/07/10
Autoionization
• Allows independent Rydberg
excitation and investigation
• Ion detection is very sensitive
5s2
5s5p
5sns(d)
Graham Lochead
19/07/10
5pns(d)
5s1/2+
Experiment plan
Need to scan across MOT
Graham Lochead
19/07/10
Lens setup
Constraints
•
•
•
•
Spot size ≤ 10μm
Lenses outside chamber
Limit decentration/tilt error
Vibrationally insensitive
Graham Lochead
19/07/10
Element
1
2
3
4
5
Focal length
-30
-30
75
250
Viewport
Translation stage
Newport miniature linear translation stage MFA-PP
• 25mm travel
• Micron accuracy stepper motor
Michelson interferometer
Graham Lochead
19/07/10
LabVIEW knife-edge program
• Test translation stage
LabVIEW drivers
• Need to check waist size
and focal position
Stage steps → averages photodiode signal → Extracts std. dev.
Fits data using error function
2 % error on waist measurement
Graham Lochead
19/07/10
Chromatic focal position shift
Alignment extremely challenging on autoionization transition
use 461 fluorescence
Chromatic shift important
Gaussian propagation fit
408 Rayleigh range ≈ size of MOT
Graham Lochead
19/07/10
Viewport aberrations
Large increase in waist size
Large increase in aberrations
Not caused by tilt
Focal position shift is achromatic
Graham Lochead
19/07/10
Outlook
• Lens system fully calibrated
• Translation stage calibrated
To do:
• Translation stage control in
main Labview sequence
• Rebuild optical setup
• EIT lock
Graham Lochead
19/07/10