ôðàíö( echelette) - îñîáûé âèä ïëîñêèõ (ãëàâíûì îáðàçîìîòðàæàòåëüíûõ) äèôðàêöèîííûõ ðåøåòîê, îáëàäàþùèõ ñïîñîáíîñòüþêîíöåíòðèðîâàòü áîëüøóþ ÷àñòü ïàäàþùåãî íà íèõ ïîòîêà èçëó÷åíèÿ âêàêîì-ëèáî îïðåäåëåííîì (íî íå íóëåâîì) ïîðÿäêå ñïåêòðà.
