Photo-associative Ionization in Rb

Stimulated Adiabatic Rapid Passage:STIRAP, the untold story

Marc TrachyMudessar Shah, Alina Gearba,

Hyounguk Jang, Larry Weaver, Brett DePaola

5S1/2 F=2

5P3/2 F=3

4D5/2 F=?

780 nm

1529 nm

Relevant Levels of 87Rb

L2

L1

Description of STIRAP

Want to see time evolution!

If No Decay

Time Evolution Theory

But can we SEE it?

Motivation

•Toy system for (for example) KLS

•Coherent control is hot

•Group satisfaction

•Technical Improvements•EDFA (Thanks LUMOS!)•Delay control•Detector replacement

Experimental Setup

4d

5p

5s

5S1/2 F=2

5P3/2 F=3

4D5/2 F=?

780 nm

1529 nm

4D5/2

5S1/2

5P3/2

L1

L2

30 ns

L2

L1

4D5/2

5S1/2

5P3/2

L1

L2

4D5/2

5S1/2

5P3/2

L1

L2

Theory (Gaussian Pulses)

Theory

• Density matrix formalism• Gaussian pulses• Zero linewidth lasers• Individual atoms

– No collisions– No rescattering of radiation

• Approximations– Rotating wave– Dipole– Near resonance (keeping it to 3 levels)

Speculation on agreement

• Radiation trapping

• Polarization (mF)

• Hyperfine separation vs detuning

• Intuitive case more like CW or incoherent

• Even a Toy system holds questions– Toys can be complicated

• Need more levels in theory• Ready for more realistic toy systems

– with CW lasers– KLS

Lessons