DISPERSION RELATIONS IN TIME-SPACE PERIODIC MEDIA: PART I. STABLE INTERACTIONS,
Abstract
Complete dispersion characteristics are exhibited for electromagnetic waves propagating in a timespace periodically-modulated medium which is all-pass and dispersionless in the absence of the (pump)modulation. A rigorous solution, including all of the infinite number of time space harmonics, is obtained for the linearized model, which also is representative of a traveling wave parametric circuit. The dispersion relation is represented graphically in a form which is a generalization of the familiar onedimensional Brillouin diagram for stationary periodic structures. From the repeated cell pattern one ascertains that for this medium only two types of interaction are possible: (1) stable interactions, of the stop-band type, associated with frequency conversion effects, and (2) potentially unstable interactions, characterized by a stop band in wavenumber rather than in frequency. These types of interaction occur, respectively, when the phase velocity of the pump modulation is less than or greater than that of a signal in the unmodulated medium. Separating these two types of interaction is a ''sonic'' region, which appears whenever these two phases velocities are approximately equal. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 11, 1963
- Accession Number
- AD0425589
Entities
People
- A. A. Oliner
- E. S. Cassedy
Organizations
- New York University Tandon School of Engineering