Electromagnetically Induced Transparency (EIT) has become an invaluable resource for numerous applications in quantum information theory, fundamental physics, nonlinear optics and precision metrology. This thesis is concerned with an extension to EIT: double- EIT, in which two separate optical fields experience EIT due to a coherence between a common ground state. Double EIT has appeared as the basis for a number of theoretical proposals but has yet to be demonstrated and analyzed experimentally. In this thesis, a double-EIT system is experimentally implemented and analyzed, using a hot vapor of rubidium-87 atoms. The interplay between the two signal fields is studied and properties are found to emerge which may prove useful for application. An application of double EIT which in principle allows large nonlinear interactions between light pulses as low as several photons per atomic cross section is discussed. Progress towards a physical demonstration of this effect is reported and prospects for further work in this direction are then described.

Some pages are in colour.

Bibliography: p. 62-65