| Ultrawide bandwidth sources of coherent light are useful for applications such as observing ultrafast chemical changes, spectroscopy, controlling chemical reactions, and nonlinear optics. Many of these applications require controllable pulses of particular temporal shape.; Over the last decade, our group has constructed a source capable of generating a discrete set of optical frequency components spanning nearly two octaves of bandwidth from the ultraviolet to the near infrared. In addition, using a liquid crystal spatial light modulator, we control the relative phases of these frequency components. This work describes the use of pulse shaping with this multioctave source for coherent control of nonlinear optical processes.; I describe an analytical technique using four-wave mixing for determining the phase relationship between frequency components (and consequently the temporal envelope) generated by this source. Using the same four-wave mixing process, I show simulations in which we are able to generate a prescribed amplitude spectrum of ultraviolet frequencies. The principle component that allows generation of arbitrary spectra is the use of a genetic algorithm to quickly find optimal pulse shapes.; I use a genetic algorithm to experimentally control nonlinear optical processes. Using a resonantly-enhanced Raman mixing process I show the ability to efficiently alter the amplitude spectrum of our source. I alter the ratio of energy between sidebands by more than a factor of 50 as well as alter individual sideband energies by millijoules. I also experimentally control properties of laser-induced optical breakdown including its timing, its location, and whether it occurs.; Finally, in the vein of source improvement, I show molecular modulation in a hollow fiber. The benefit of the fiber is that it requires 20 times less drive energy to be efficient allowing more stable, cheaper, higher repetition rate drive lasers.; Together, these experiments and simulations show progress towards being able to fully measure and control Ultrawide bandwidth light sources. I experimentally demonstrate some of the novel processes which can be coherently controlled with a multioctave source as well as show techniques which could be used to generate new ultrabroad bandwidth sources. |
