Evolutionary Pulse Shaping in CARS Signal Enhancement
We discuss the role of evolutionary adaptive algorithms in shaping femtosecond pulses with an eye toward their use in the quantum control of optical properties. In particular, we report preliminary results from an ongoing attempt to implement the recently proposed FAST CARS technique for the detection and identification of bacterial spores. In the initial phase of this project, we are studying the CARS signal from a deuterated water (D2O) solution of Dipicolinic Acid (DPA), which is an important constituent of the spores. We have detected CARS signal associated with the DPA vibrational resonances at ∼ 1,600 and ∼ 3,000cm-1. We also find preliminary evidence of a pulse shaping enhancement of the CARS intensity. This effect is weak, but significant. It is premature to ascribe it to any particular mechanism, but its detection encourages its optimization by searching the space of all possible pulse shapes via an evolutionary feedback algorithm.
