PRINCIPLES OF LASERS OptoSci's ED-LASE educator kit, enables students to consolidate their knowledge and understanding of optical amplification and lasers through experimental investigation of the laser output as a function of the major design parameters. Options: LASE(MODULE): Extension to ED-AMP The experimental investigation addresses: Construction of a fibre ring laser Measurement of lasing threshold Laser dynamics: relaxation oscillations, excitation lifetime, laser onset time Measurement of slope efficiency Effect of intra-cavity loss on the slope efficiency and threshold Influence of output coupling ratio on slope efficiency and threshold