Kalsium Fluoride (CaF2)
Nā Lens Bi-Concave

ʻO nā lens Bi-concave a i ʻole Double-concave (DCV) nā lens maikaʻi ʻole i ʻoi aku ka mānoanoa ma ka ʻaoʻao ma mua o ka waena, ke hele ka mālamalama ma o lākou, ʻokoʻa ia a ʻo ke kiko kikoʻī he virtual. Loaʻa i nā lens Bi-Concave ka radius like o ka curvature ma nā ʻaoʻao ʻelua o ka ʻōnaehana optical, ʻaʻole maikaʻi ko lākou mau kikoʻī, a me ka radii o ka curvature o nā ʻaoʻao curved. ʻO ka lōʻihi kikoʻī maikaʻi ʻole e hoʻokaʻawale i ka mālamalama hanana collimated, hoʻohana pinepine ʻia lākou e hoʻokaʻawale i kahi kukui convergent. Ma muli o ko lākou mau hiʻohiʻona, hoʻohana mau ʻia nā lens bi-concave no ka hoʻonui ʻana i ka mālamalama i loko o nā mea hoʻonui kukui ʻano Galilaia a i ʻole e hoʻonui i ka lōʻihi kiko o ka lens converging ma o ka hoʻohana pālua ʻana i nā ʻōnaehana e kū nei e like me nā ʻōnaehana projection māmā. He mea maikaʻi nō hoʻi lākou i ka hōʻemi ʻana i ke kiʻi. I loko o nā ʻōnaehana optical, he mea maʻamau ke koho pono ʻana i kā lākou optics i hiki ke hoʻopau ʻia nā aberrations i hoʻokomo ʻia e nā lens-focal-lōʻihi maikaʻi a maikaʻi ʻole. Hoʻohana pinepine ʻia kēia mau lens maikaʻi ʻole i nā telescopes, nā kamera, nā lasers a i ʻole nā ​​aniani e kōkua i nā ʻōnaehana hoʻonui e ʻoi aku ka paʻakikī.