Analysis of optical and terahertz multilayer systems using microwave and feedback thoery

The principles of microwave and feedback theory are independently applied to the analysis of both optical and terahertz‐regime multilayer systems. An analogy between the two approaches is drawn, and useful recursion relations, along with a signal‐flow approach, are presented for both reflection and transmission cases. These relations, in terms of S‐parameters, allow an exact analytical solution for even arbitrary, active, stratified structures, not only for any wavelength in the radio‐frequency spectrum, but also for optical wavelengths. This approach also provides a bridge between the microwave and optical bands and leads to beneficial design solutions for intermediate bands such as the THz regime. Comparisons with conventional methodologies are provided using practical multilayer simulations. In addition, graphical design techniques from microwave theory are used along with examples for efficient design and understanding. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1308–1312, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24301