Metasurface-assisted phase-matching-free second harmonic generation in lithium niobate waveguides.

See more Lithium products. Lithium (atomic symbol: Li, atomic number: 3) is a Block S, Group 1, Period 2 element with an atomic weight of 6.94. The number of electrons in each of Lithium's shells is [2, 1] and its electron configuration is [He] 2s¹. The lithium atom has a radius of 152 pm and a Van der Waals radius of 181 pm. Lithium was discovered by Johann Arvedson in 1817 and first isolated by William Thomas Brande in 1821. The origin of the name Lithium comes from the Greek wordlithose which means "stone." Lithium is a member of the alkali group of metals. It has the highest specific heat and electrochemical potential of any element on the period table and the lowest density of any elements that are solid at room temperature. Compared to other metals, it has one of the lowest boiling points. In its elemental form, lithium is soft enough to cut with a knife its silvery white appearance quickly darkens when exposed to air. Because of its high reactivity, elemental lithium does not occur in nature. Lithium is the key component of lithium-ion battery technology, which is becoming increasingly more prevalent in electronics.

See more Niobium products. Niobium (atomic symbol: Nb, atomic number: 41) is a Block D, Group 5, Period 5 element with an atomic weight of 92.90638. The number of electrons in each of niobium's shells is 2, 8, 18, 12, 1 and its electron configuration is [Kr] 4d⁴ 5s¹. The niobium atom has a radius of 146 pm and a Van der Waals radius of 207 pm. Niobium was discovered by Charles Hatchett in 1801 and first isolated by Christian Wilhelm Blomstrand in 1864. In its elemental form, niobium has a gray metallic appearance. Niobium has the largest magnetic penetration depth of any element and is one of three elemental type-II superconductors (along with vanadium and technetium). Niobium is found in the minerals pyrochlore, its main commercial source, and columbite. The word Niobium originates from Niobe, daughter of mythical Greek king Tantalus.