(For the uninitiated in the field, see below for details and description)

(---The calculator was created by N. Ph. Georgiades and is implemented using Java.---)

I. Instructions:

• Press Example 1-16 buttons to see some interesting cases of QI.
• Adjust any parameters and press GO to see the resulting graph (make sure that all text fields have valid entries, by default the variable is indicated by "-VAR-".)
• Note that when using the FULL theory model, the value of d0 is automatically adjusted to be d0=(d1+d2)/2 which implies that the triangle condition 2d0-d1-d2=0 holds. For more details see our paper(Abstract 2)

II. Brief Introduction to QuInC:

We have performed a theoretical analysis of the problem of two-photon excitation by three laser fields as described in our previous publications N.Ph.Georgiades, E.S.Polzik and H.J.Kimble, Optics Letters, v.21, 1688, (1996) (Abstract) and N.Ph.Georgiades, E.S.Polzik and H.J.Kimble, PRA Rapid Communications, March (1997) (Abstract) and which describe our experimental results. In addition, we have performed a theoretical analysis of the problem that will be published in a sequence of papers in PRA (Abstract 1, Abstract 2). Our theory is divided into two parts: First a perturbation solution to the problem and second a more complete ("full") theory that accounts for saturation of the atoms.

Here, we present an interactive "Quantum Interference Calculator" which allows the user to change several parameters of the problem and calculate characteristics of the resulting Quantum Interference.

III. Physical System

Quantum Interference in Two-Photon Excitation by 3 Lasers :

Atoms can be excited to the upper level via two possible excitation paths:

1. Two dipole absorptions of single photons from the w1 and w2 lasers
2. One quatrupole two-photon absorption from the w0 laser
The presence of these two alternative excitation paths leads to a fringe pattern due to Quantum Interference of their amplitudes. It can be controlled and modulated by adjusting the relative frequency and phase of the exciting lasers

System Parameters:

• Atomic Eigenfrequencies....: w12, w23 and w13
• Atomic Linewidths.............: g2 and g3 (in MHz)
• Laser Frequencies..............: w1, w2 and w0
• Detunnings.........................: d1, d2 and d0 (defined byd1=w1-w12, d2=w2-w23 and d0=w0-1/2*w13)
• Non-Degeneracy Distance..: D=|1/2*w13-w12|=|1/2*w13-w23|
• Laser Intensities *...............: W1, W2 and Qo
* These are the Rabi Frequencies in dimensionless form as defined in the theory papers to come. Roughly speaking W1~1 saturates the 1->2 transition, W2~1 saturates the 2->3 transition and similarly Qo~1 saturates the two photon transiton1->3)

Excitation Diagram:

Copyright: The above page and calculator were created by Nikos Ph. Georgiades. To contact me send e-mail to: nikosg@cco.caltech.edu