Figure 5.10, If we consider light as a wave with amplitude A and wavelength λ, we observe that amplitude objects reduce the wave amplitude by absorption. Phase objects cause a phase shift
Reciprocity between phase shifts and amplitude changes in the mammalian circadian clock | PNAS
Prismatic Phase Shifter - Tech Briefs
Thin-film interference
Amplitude, Frequency, Wave Number, Phase Shift | Brilliant Math & Science Wiki
Phase Change on Reflection To understand interference caused by multiple reflections it is necessary to consider what happens when a light wave moving. - ppt download