拍開主題選單

Pho-tn̂g (Eng-gí: wavelength) tī bu̍t-lí-ha̍k siōng, sī chiàⁿ-hiân-pho pho-tōng ê khong-kan chiu-kî, iā tiō sī pho-tōng hêng-thé têng-ho̍k ê hn̄g-kīn (distance).