▁cav ities . ▁ ▁The ▁discrete ▁energy ▁levels ▁of ▁elect romagnet ic ▁cav ities ▁are ▁explo ited ▁to ▁produce ▁phot ons ▁of ▁desired ▁frequencies ▁and ▁thus ▁are ▁essential ▁for ▁n ano - ▁or ▁subm ic rom et re - scale ▁las er ▁devices . ▁ ▁See ▁also ▁▁▁ ▁Cav ity ▁reson ator ▁ ▁C rab ▁cav ity ▁ ▁Sch umann ▁reson ance ▁ ▁Opt ical ▁cav ity ▁ ▁Quant um ▁dot ▁ ▁References ▁▁ ▁Category : E lect romagnet ism <0x0A> </s> ▁Ber gen ▁Township ▁was ▁a ▁town ship ▁that ▁existed ▁in ▁Ber gen ▁County , ▁New ▁Jersey . ▁The ▁town ship ▁was ▁created ▁on ▁February ▁ 2 1 , ▁ 1 8 9 3 , ▁from ▁the ▁southern ▁section ▁of ▁L odi ▁Township ▁( now ▁South ▁H ack ens ack ): ▁ ▁Another ▁town ship ▁with ▁the ▁same ▁name , ▁Ber gen ▁Township , ▁was ▁created ▁ 2 0 0 ▁years ▁earlier . ▁ ▁The ▁bor ough ▁of ▁Carl stadt ▁was ▁formed ▁on ▁June ▁ 2 7 , ▁ 1 8 9 4 , ▁from ▁port ions ▁of ▁the ▁town ship , ▁at ▁the ▁height ▁of ▁the ▁Bor ough itis ▁phenomen on ▁then ▁swe eping ▁through ▁Ber gen ▁County . ▁ ▁The ▁bor ough ▁of ▁Wood - R idge ▁was ▁created ▁on ▁December ▁ 6 , ▁ 1 8 9 4 , ▁from ▁within ▁the ▁town ship , ▁followed ▁shortly ▁there after ▁by ▁the ▁bor ough ▁of ▁Wall ington , ▁which ▁was ▁formed ▁on ▁January ▁ 2 , ▁ 1 8 9