Laser plasma interaction can be used to generate extremely strong and localized electromagnetic fields. Fields in excess of 100GV/m are routinely generated in small regions with dimensions in the order of microns. These fields can in turn generate charged particle beams of comparable dimensions moving with relativistic velocities. These ultrashort, tightly focused, and often structured beams are capable of delivering high current and/or power beams within order of femtoseconds, making them promising for applications such as nuclear fusion, pulsed neutron generation, electromagnetic radiation generation, and cancer therapy. This dissertation presents two different mechanisms for generating such par-ticle beams consisting of electrons or ions using laser-plasma interaction. Simple analytical models to describe the respective processes and guide experimental implementations are developed. First-principle particle-in-cell simulation re- sults are presented to support the analytical predictions, with parameters relevant to State-of-the-Art laser systems. Chapter 2,3 presents the Carrier-Envelope-Phase(CEP) controlled electron injection mechanism into an (Expanding) Periodically Undulating Bubble ((E)PUB). When an intense near-single-cycle laser pulse or a self-steepened pulse propagates in plasma, it can excite a periodically undulating plasma bubble propagating close to speed of light. The undulation can trigger or suppress electron injection into the plasma bubble, generating longitudinally modulated ultra-relativistic beams with periodicity close to or shorter than a laser wave length. Chapter 2 considers a long-wavelength near-single cycle laser copropa gating with a shorter-wavelength multi-cycle pulse. During the initial stage of propagation, the near-single cycle laser generates periodic undulations, injecting several ultrashort bunches with sub-femtosecond durations. It quickly loses energy to the plasma, and the multi-cycle pulse stably accelerates the injected electrons to a higher energy. Chapter 3 considers a different implementation where a high-power few-cycle laser pulse self-steepens. In this scenario, the plasma bubble undergoes both undulation and expansion, and the electron is in- jected into a dynamically evolving bubble which traps and accelerates the electrons throughout the laser propagation in the plasma. Semi-analytical Hamiltonian model is developed to model both cases, showing good agreement with the First-Principles simulation results. The injected bunch profile can be controlled via the laser’s CEP, polarization, power, and plasma density, and provides a robust platform for controlling the electron beam’s spatio-temporal profile. Chapter 4 explores how the hole-boring radiation pressure acceleration (HB-RPA) mechanism of ion acceleration can be used to focus and accelerate ion beams to a few-micron spot size. When a circularly polarized laser is incident on a overdense plasma surface, it initially pushes away the opaque electrons forward. The ions are then dragged forward via the charge-separation force. It turns out that adequate front-surface shaping, i.e. a parabolic shape, can accel- erate and focus a large flux of ions into a well-defined focal length. Furthermore, a relatively flat laser transverse intensity profile can maintain the focusing front-surface, enabling a high-flux ion beam that can focus at an arbitrary focal length. The scheme is applicable for a wide power range of lasers, ranging from sub-PW to tens-of-PW laser systems and can accelerate multi-species ion beams, forming a monoenergetic ion beam. The accelerated multispecies ion beam copropagating with the electron evolves due to the coupling between the hot electron pressure and massive ions, setting the limit to focusing. We conclude with future directions for research, including open questions and considerations for experimental implementation.