Preparation of highly vibrationally excited (v greater than or equal to 4) H2 molecules by Stark induced adiabatic Raman passage (SARP))
Abstract
We are proposing an efficient method of preparing a highly vibrationally excited H2 (v = 4, 11) molecule within its ground electronic state using our newly invented Stark induced adiabatic Raman passage (SARP). Our detailed theoretical study suggests that SARP can achieve a large population transfer (> 50%), from the ground rovibrational state H2 (v=0, J=1) to a highly vibrationally excited state H2 (v=11, J=1), using a sequence of partially overlapping visible pump (532 nm) and Stokes (near 680 nm) pulses with fluences of a few Joule/mm2. The entangled yet loosely bound H atoms in a highly vibrationally stretched H2 molecule open completely new possibilities for the field of coherently controlled reaction dynamics. Our first effort in this direction will start with the SARP preparation of H2 or HD (v = 4) by combining a 355 nm single mode pump pulse with a delayed single mode Stokes pulse near 700 nm. Theory predicts that the complete population of the HD (v=0, J=0, 1) can be transferred to HD (v=4, J=2, 3) using the nanosecond pump and Stokes pulses with energy of a few J/mm2. By combining different polarizations of the pump and Stokes laser pulses we will also prepare the superposition of the degenerate M-states within a single rotational state of a highly excited vibrational level of H2. The coherent superposition of M-states will allow us to coherently control the stereo dynamics of molecular collisions using the highly vibrationally excited H2. In this effort, although we consider the preparation of specific high vibrational states of H2 using currently operational laser wavelengths in our laboratory, the procedure developed here will be applicable to prepare any high vibrational level using the appropriate set of wavelengths from commercially available laser sources.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1610161
Entities
People
- Richard Zare
Organizations
- Army Contracting Command
- Stanford University
- United States Army