Self-pulsating laser diodes emitting at 650 and 420 nm are currently in demand in the optical storage industry. Such lasers offer emission with a low temporal coherence length, thereby providing a cheap and efficient mechanism of reading data from an optical disc. Laser diodes operating at 650 nm are fabricated in the A1GalnP material system; however, material properties hinder self-pulsation at 70 °C, an operating constraint that must be satisfied. To overcome this problem the use of alternative, more expensive, techniques are utilised to achieve pulsation and satisfy the emission criteria. Research involving 420 nm emission, using either GaN or ZnSe material systems, is still in its infancy with self-pulsation having been somewhat neglected. It is therefore desirable to achieve high temperature self-pulsation at both operating wavelengths in order to provide economic and compact mechanisms of reading data from optical discs. This thesis offers a theoretical investigation of visible emitting self-pulsating laser diodes to provide an insight into the viability of the use of such lasers in optical storage devices. The work is split into two sections. The first part gives a thorough, detailed study of self-pulsation, analysing the theory required to understand the mechanisms behind such unstable output. The design and attributes of self-pulsating laser diodes are discussed combined with the theory used to model the dynamics of such lasers when operating at different wavelengths. Attention will be directed towards two of the most advanced self-pulsating structures, namely the real refractive index guided laser and the laser diode with epitaxial absorber layers. The second part implements the theoretical models to study and optimise the emission characteristics of different self-pulsating lasers for optical storage applications. Three lasers are considered - two operating at 650 nm and the other at 420 nm. In each case the laser is initially investigated for self-pulsation at 70 °C. If successful the cavity design is then optimised subject to other well-defined operating constraints, thereby providing an assessment of the most desirable structures. As a result, the work offers a clear indication of the suitability of short wavelength self-pulsating laser diodes as economical read-out mechanisms within optical storage devices.