▁fewer ▁than ▁one ▁detected ▁phot on ▁per ▁image ▁pixel . ▁ ▁Phot on - s parse ▁micro sc opy ▁with ▁inf ra red ▁light ▁Inf ra red ▁cam eras ▁that ▁combine ▁low - no ise ▁with ▁single - ph ot on ▁sens itivity ▁are ▁not ▁readily ▁available . ▁Inf ra red ▁ill um ination ▁of ▁a ▁vulner able ▁target ▁with ▁sparse ▁phot ons ▁can ▁be ▁combined ▁with ▁a ▁camera ▁counting ▁visible ▁phot ons ▁through ▁the ▁use ▁of ▁g host ▁imag ing ▁with ▁correl ated ▁phot ons ▁that ▁have ▁significantly ▁different ▁w avel ength s , ▁generated ▁by ▁a ▁highly ▁non - de generate ▁SP DC ▁process . ▁Inf ra red ▁phot ons ▁with ▁a ▁w avel ength ▁of ▁ 1 5 5 0   nm ▁ill uminate ▁the ▁target ▁and ▁are ▁detected ▁by ▁an ▁In G a As / In P ▁single - ph ot on ▁a val anche ▁di ode . ▁The ▁image ▁data ▁are ▁recorded ▁from ▁the ▁coinc ident ly ▁detected , ▁position - cor related , ▁visible ▁phot ons ▁with ▁a ▁w avel ength ▁of ▁ 4 6 0   nm ▁using ▁a ▁highly ▁efficient , ▁low - no ise , ▁phot on - count ing ▁camera . ▁Light - sens itive ▁bi ological ▁samples ▁can ▁thereby ▁be ▁im aged . ▁ ▁Rem ote ▁sens ing ▁Ghost ▁imag ing ▁is ▁being ▁considered ▁for ▁application ▁in ▁remote - sens ing ▁systems ▁as ▁a ▁possible ▁compet itor ▁with ▁imag ing ▁las er ▁rad ars ▁( L ID AR ). ▁A ▁theoretical ▁performance