Ultrafast light bursts comprising a few oscillation cycles of electromagnetic fields, when focused, give rise to unprecedented light intensity levels with extreme temporal resolution. This book presents an experimental investigation of the interaction of intense and moderately intense laser pulses with novel forms of matter, namely metal nanostructures and plasmas. First few chapters describe the investigations of nonlinear optical properties of metal nanoparticles and nanowires using nanosecond and femtosecond laser pulses. A fast and simple method for estimating the sign of refractive optical nonlinearity in a nonlinear film is presented in the following chapter. The use of white light continuum as a tool for measuring the spectral dispersion of optical nonlinearity in materials is discussed afterwards. Application of ultrafast, intense laser pulses for creating plasmas in solid and liquid targets, and investigation of the emitted x-ray spectrum from these laser produced plasmas are discussed in the final chapters.