Date of Award


Degree Name

Master of Science



First Advisor

Dr. Alvin Rosenthal

Second Advisor

Dean Halderson

Access Setting

Masters Thesis-Open Access


When a beam of light propagates within a typical medium, absorption is a common phenomenon. This happens when the frequency of the light is close to a resonant frequency of the atoms composing the medium. But in the past few decades, it has been shown that in certain circumstances, carefully chosen pulse shapes are able to propagate without significant absorption even when the frequency of the light is close to an atomic resonant frequency. It was called Self Induced Transparency (SIT).

This phenomenon was intensively studied in the two-state systems. On the other hand, the three-state systems seems not to have the same amount of attention from physicist around the world. Our work is manly concentrated on the three-state solitons. We will derive a set of density matrix equations of motion using reasonable physical approximations. These equations are nonlinear partial differential equations for the amplitude envelopes of two laser light beams. This thesis will be concerned with a first look at these equations, neglecting detuning and damping. We will show a variety of numerical solutions for this case. Some of them are normal pulses that we call "single-pulse solitons", others have periods for one of the laser fields that differ by a factor of two from the other field, and still others have a novel shape, which we call "envelope-pulse solitons".