what wavelengths are used in photosynthesis
It turns out that virtually no light with wavelengths longer than 690 nm is converted or captured by chlorophyll or carotenoids. Also, some light of shorter wavelengths than what humans can see is used by photosynthesis. Chlorophyll-a, chlorophyll-b and carotenoids all use light of wavelengths shorter than 390 nm. Interestingly, Chlorophyll-a can use light with wavelengths as short as 350 nm. This is getting into the UV or ultraviolet (above or beyond violet) range. For practical purposes, photosynthesis in general utilizes wavelengths of light from about 380 nm to 690 nm.