Transmission

1
Theoretical Optimization of a DAVLL System for a
Rubidium Vapor
Joel A. Greenberg, Andrew M. C. Dawes, Daniel J.
Gauthier
Quantum Electronics Lab, Physics Department, Duke
University
Introduction
Experimental Data
Here we show sensitivity to B field changes
MOTIVATION
Experimental Setup

• Model and optimize a simple, robust, laser
  frequency lock system

METHOD
Dichroic Atomic Vapor Laser Lock (DAVLL) 1
Temp (K)

• Zeeman effect shifts energy levels
• Resonant frequencies shift down/up for s/s-

Model vs. Experiment
Absorption Scan
Difference Signal

• Subtracting the shifted absorption signals
  produces a dispersion-like curve suitable as an
  error signal

Diff Signal
Transmission
Absorption Profile
Difference Signal
Conclusions
s - s-
s-
s
Frequency (MHz)
Frequency (MHz)
Optimal conditions for a D2 lock in a 7.5cm Rb87
cell
B260 G, T335 K
Optimization

• Slope 2 GHz-1

• Capture range 0.5 GHz

GOALS

• Choose the combination of B and T which
• Provides a large but insensitive slope
• Provides a difference signal with an insensitive
  lock point
• Produces a signal which is suitably linear
• Produces a broad capture range

• Within 5 K and 2.5 G of the optimum
  conditions, the signal fluctuates as
• slope sensitivity lt0.5 (1/GHz)/K
  lt0.1 (1/GHz)/G
• lock point sensitivity 0 10 KHz/K
  50 50 KHz/G
• capture range variation 0 20 MHz/K
  4 1 MHz/G

Sensitivity of Slope to T
GHz-1/K
Here we show sensitivity to temperature changes
Temp (K)
The Model
B Field(G)
Sensitivity of Lock Pt to T
MHz/K
Citations 1) Corwin, Lu, Hand, Epstein, Wieman
Appl. Opt. 37, 3295 (1998) 2) Beverini, Marsili,
Ruffini, Sorrentino Appl. Phys. B 73, 133-138
(2001)
Hamiltonian
Output intensity 2
Temp (K)
Funding US Army Research Office (grant
W911NF-05-1-0228)