A monolithic laser cavity (100, 200, 300, 400) for generating an output series of pulses (37) based on an input pump signal 36. This is achieved by a novel cavity design that utilizes a transparent, low-loss, and near zero-dispersion spacer (38) to form an optical resonator without the use of wave-guiding effects. The pulse forming material (32), optical elements (10-16, 30, 31, 33), and the laser gain medium (34) are in direct contact with the spacer and/or each other without any free-space sections between them. Therefore, the light inside the laser cavity never travels through free space.