The niobium oxide dihalides have recently been identified as a new class of van der Waals materials exhibiting exceptionally large second-order nonlinear optical responses and robust in-plane ferroelectricity. In contrast to second-order nonlinear processes. third-order optical nonlinearities can arise irrespective of whether a crystal lattice is centrosymmetric. Here. https://mylittlewardrobers.shop/product-category/rompers/