In this thesis, the dependence of the ablation dynamics on the most important laser parameters and the implied consequences for micro/nano structuring was studied in detail. Of particular interest was the dependence on the pulse durations which are in the range of 10's of femtoseconds to <10 femtoseconds, now deliverable by commercially available laser systems. Ablation threshold fluence is an important parameter that can give insight into the physical processes taking place in a material. Knowing the values is also necessary to deposit a defined amount of energy for precision material processing applications. The value is dependent on the type of material, on the laser pulse duration and on the number of pulses. In this work a systematic study was done to investigate the influence of pulse duration and pulse number on the ablation thresholds for three different types of materials: metal (copper), semiconductor (silicon) and bio-polymer (gelatin) in 10 fs - 550 fs range. The results indicate that the threshold fluence reduces with decreasing the pulse duration. The dependence of the threshold fluence on the pulse duration was determined as F_th is proportional to (tau)^ duration. Extensive measurements were done to find the velocities of the neutral particles that are emitted when irradiated with pulses of 10 fs to 550 fs. The results show that neutrals with energies in excess of few eV are detected. This cannot be explained if we donot consider the fast non-thermal processes like coulomb explosion and ultrafast melting. The velocities (energies) with which neturals are emitted from different metals and semiconductors is reported. When an ultrafast laser irradiates a material, a wide variety of structures are formed. The most interesting structures are conical structures and periodic ripples. In bio-polymers, scaffold-like structures are formed. As part of this work, structures were produced on a wide variety of materials (titanium, steel, tin, nickel, copper, molybdenum, silicon etc., and on bio-polymers like gelatin and collagin etc.). A systematic study was done to characterize the laser-induced periodic surface structures (LIPSS), both the low-spatial frequency LIPSS (LSFLs) and the high-spatial frequency LIPSS (HSFLs), and their dependence on various laser parameters. Scaffold-like structures that mimic the extracellular matrix, were produced on bio-polymer films and were studied for the suitability of tissue engineering. The cell seeding experiments showed that cell mobility and adaptability were dependent on the topography. We demonstrated that the micro-pores', dimensions formed on the scaffolds can be tuned in a controllable way by altering the laser parameters.