We present the results of Material Point Method (MPM) computer simulations of AK-47 bullet impacts on composite ceramic protective vests with Kevlar and spider web fibers. The algorithm is coded in C++ and involves varying composition and dimensions of the vest as well as the bullets, with up to 1.2 million particles in the simulations. Results suggest that the program is very sensitive to material breaking points and nominally sensitive to finite size effects.

Fiber lasers using saturable absorption in a semiconductor mirror can produce optical pulses on the order of picoseconds in an all-fiber configuration. My talk will review the components of this fiber-laser and how they work to produce ultrafast pulses. In addition to showing experimental results, I will review some of the theory and background of mode-locked fiber-lasers, particularly the semiconductor saturable absorber mirror configuration.

Using the frequency domain rather than the time domain as an alternate means of measuring the extinction ratio for ultrafast pulsed lasers.