Amplitude is the maximum displacement of a wave from its central, undisturbed axis. For light it corresponds to the brightness or intensity of the radiation. Amplitude is independent of wavelength and frequency, which instead determine the wave's energy per photon and its position in the spectrum.

振幅是波相对其中心(未受扰动)轴的最大位移。对于光,它对应于辐射的亮度或强度。振幅与波长和频率无关,后两者则决定波的每个光子能量及其在波谱中的位置。