Laser pulse design using optimal control theory-based adaptive simulated annealing technique: vibrational transitions and photo-dissociation

Abstract

We have designed and optimised a combined laser pulse using optimal control theory-based adaptive simulated annealing technique for selective vibrational excitations and photo-dissociation. Since proper choice of pulses for specific excitation and dissociation phenomena is very difficult, we have designed a linearly combined pulse for such processes and optimised the different parameters involved in those pulses so that we can get an efficient combined pulse. The technique makes us free from choosing any arbitrary type of pulses and makes a ground to check their suitability. We have also emphasised on how we can improve the performance of simulated annealing technique by introducing an adaptive step length of the different variables during the optimisation processes. We have also pointed out on how we can choose the initial temperature for the optimisation process by introducing heating/cooling step to reduce the annealing steps so that the method becomes cost effective.

Keywords:

• design and optimisation of combined laser pulse
• vibrational excitation
• photo-dissociation
• simulated annealing
• TDFGH
• HBr⁺

Acknowledgements

The authors thank Dr P. Chowdhuri, University of Calcutta, for the necessary discussion on algorithm.

Additional information

Funding

The authors thank UGC, Govt. of India, for the financial support through CAS program [Grant No. F.540/1/CAS/2007(SAP1)].