Abstract: A compact laser oscillator-amplifier system comprising an oscillator section including slab laser medium (1) with laser beam reflecting coating (4) operating in an open cavity configuration with a bevelled substrate (8) having laser beam reflecting surface (7) and including bevelled end surfaces (11) and end mirrors (12). Coupled to the laser oscillator via polarizing prism (14) and mirror (15) is an amplifier section of similar construction which includes slab laser medium (2). The oscillator and amplifier laser media (1, 2) are excited by a common optical excitation source (3) which is positioned between the oscillator and amplifier sections and which directs light through optical filters (9) to the laser slabs (1, 2).