▁when ▁exc itation ▁w avel ength s ▁in ▁the ▁near ▁inf ra red ▁are ▁used . ▁ ▁Im aging ▁devices ▁ ▁F GS ▁is ▁performed ▁using ▁imag ing ▁devices ▁with ▁the ▁purpose ▁of ▁providing ▁real ▁time ▁simultane ous ▁information ▁from ▁color ▁reflect ance ▁images ▁( br ight ▁field ) ▁and ▁flu ores c ence ▁emission . ▁One ▁or ▁more ▁light ▁sources ▁are ▁used ▁to ▁ex cite ▁and ▁ill uminate ▁the ▁sample . ▁Light ▁is ▁collected ▁using ▁optical ▁filters ▁that ▁match ▁the ▁emission ▁spectrum ▁of ▁the ▁flu or oph ore . ▁Im aging ▁l enses ▁and ▁digital ▁cam eras ▁( CC D ▁or ▁C M OS ) ▁are ▁used ▁to ▁produce ▁the ▁final ▁image . ▁ ▁Live ▁video ▁processing ▁can ▁also ▁be ▁performed ▁to ▁enh ance ▁contrast ▁during ▁flu ores c ence ▁detection ▁and ▁improve ▁signal - to - background ▁ratio . ▁ ▁In ▁recent ▁years ▁a ▁number ▁of ▁commercial ▁companies ▁have ▁emer ged ▁to ▁offer ▁devices ▁special izing ▁in ▁flu ores c ence ▁in ▁the ▁N IR ▁w avel ength s , ▁with ▁the ▁goal ▁of ▁capital izing ▁upon ▁the ▁growth ▁in ▁off ▁label ▁use ▁of ▁ind oc yan ine ▁green ▁( IC G ). ▁ ▁However ▁commercial ▁systems ▁with ▁multiple ▁flu ores c ence ▁channels ▁also ▁exist ▁commer cially , ▁for ▁use ▁with ▁flu ores ce in ▁and ▁pro top orph yr in ▁IX ▁( P p IX ). ▁ ▁Ex c itation ▁sources ▁ ▁Fl u ores c ence ▁exc itation ▁is ▁accomplished ▁using ▁various ▁kind ▁of ▁light ▁sources . ▁Hal