Nonlinear optical effects in carbon suspensions

In this report we examine how the fluid host influences the nonlinear optical response of carbon black suspensions on both the nanosecond and microsecond timescales. It is shown that there is a strong fluid dependence on the microsecond timescale and a smaller but still significant dependence on the nanosecond timescale. The temporal dynamics are studied and it is proposed that bubble formation is responsible for the enhanced microsecond response observed in the more volatile fluids. A beam propagation scheme is introduced and it is demonstrated that by making simple assumptions about the microscopic nonlinear loss mechanism the experimental data can be simulated.