▁gal li um ▁ar sen ide ▁cry stal . ▁Starting ▁at ▁a ▁light ▁w avel ength ▁of ▁ 8 5 0   nm ▁Ga As ▁becomes ▁opt ically ▁transl uc ent . ▁Since ▁the ▁spectral ▁position ▁of ▁the ▁band ▁gap ▁is ▁temperature ▁dependent , ▁it ▁sh ifts ▁about ▁ 0 . 4   nm / K . ▁The ▁measurement ▁device ▁contains ▁a ▁light ▁source ▁and ▁a ▁device ▁for ▁the ▁spectral ▁detection ▁of ▁the ▁band ▁gap . ▁With ▁the ▁changing ▁of ▁the ▁band ▁gap , ▁( 0 . 4   nm / K ) ▁an ▁algorithm ▁calcul ates ▁the ▁temperature ▁( all ▁ 2 5 0 ▁ms ). ▁ ▁Sp in - charge ▁conver ters ▁Ga As ▁may ▁have ▁applications ▁in ▁spin tr on ics ▁as ▁it ▁can ▁be ▁used ▁instead ▁of ▁plat in um ▁in ▁spin - charge ▁conver ters ▁and ▁may ▁be ▁more ▁tun able . ▁ ▁Saf ety ▁The ▁environment , ▁health ▁and ▁safety ▁aspects ▁of ▁gal li um ▁ar sen ide ▁sources ▁( such ▁as ▁trim eth yl gal li um ▁and ▁ar s ine ) ▁and ▁industrial ▁h yg iene ▁monitoring ▁studies ▁of ▁metal organ ic ▁prec urs ors ▁have ▁been ▁reported . ▁California ▁lists ▁gal li um ▁ar sen ide ▁as ▁a ▁car cin ogen , ▁as ▁do ▁I AR C ▁and ▁E CA , ▁and ▁it ▁is ▁considered ▁a ▁known ▁car cin ogen ▁in ▁animals . ▁On ▁the ▁other ▁hand , ▁a ▁ 2 0 1 3 ▁review ▁( fund ed ▁by ▁industry ) ▁argued ▁against ▁these