phasematch
Phasematch is a term that can refer to several concepts, primarily within the fields of optics and signal processing, all relating to the alignment or synchronization of phases. In optics, particularly in the context of lasers and interferometry, phasematch refers to the condition where the phase relationship between interacting light waves is maintained in a specific way. This is crucial for phenomena like nonlinear optical processes, such as second-harmonic generation, where the conversion efficiency depends heavily on maintaining a constant phase difference between the fundamental and generated waves as they propagate through a medium. Achieving phasematch often involves careful selection of materials, temperatures, or angles of incidence.
In signal processing, phasematch can describe the process of aligning the phase of one signal with another.