A method for growing long-seed DKDP crystal by two-dimensional motion grows the crystal along the cylindrical surface, and there is no cylinder-cone interface with low optical quality, while avoiding three flow regions which are inevitable in the crystal growth process by rotating crystal method, including incident flow, side flow and wake flow, and easily cause inclusion formation. The long seed crystal moves periodically in the fresh solution, four cylindrical surfaces can achieve reversible shear flow in one cycle, and any point on the cylindrical surface experiences the same hydrodynamic conditions in one movement cycle, so that the solute supply is sufficient and uniform, the growth velocity is improved, and the stability of morphology is ensured. The method facilitates rapid growth of high quality DKDP crystals and provides a better solution for the large-size, high-quality DKDP crystal growth required by the ICF laser device.

A multilayer structure of the present invention is a multilayer structure including a base substrate and a semiconductor film that is made of α-Ga.sub.2O.sub.3 or an α-Ga.sub.2O.sub.3-based solid solution and has a corundum crystal structure, the semiconductor film being disposed on the base substrate. The semiconductor film has an average film thickness of greater than or equal to 10 μm. The semiconductor film is convexly or concavely warped. An amount of warpage of the semiconductor film is 20 μm or greater and 64 μm or less.

A multilayer structure of the present invention is a multilayer structure including a base substrate and a semiconductor film that is made of α-Ga.sub.2O.sub.3 or an α-Ga.sub.2O.sub.3-based solid solution and has a corundum crystal structure, the semiconductor film being disposed on the base substrate. The semiconductor film has an average film thickness of greater than or equal to 10 μm. The semiconductor film is convexly or concavely warped. An amount of warpage of the semiconductor film is 20 μm or greater and 64 μm or less.

A Ga.sub.2O.sub.3-based semiconductor device includes a Ga.sub.2O.sub.3-based crystal layer including a donor, and an N-doped region formed in at least a part of the Ga.sub.2O.sub.3-based crystal layer.

A Faraday rotator and an optical isolator having a high transmittance and a high Verdet constant are provided. The optical isolator includes at least a Faraday rotator that rotates a polarization plane of incident light in a non-reciprocal manner, a polarizer disposed on a light incident side of the Faraday rotator, and an analyzer disposed on a light exit side of the Faraday rotator. The Faraday rotator is made of an oxide containing ytterbium oxide (Yb.sub.2O.sub.3), and is manufactured by a ceramic manufacturing process, wherein the oxide is allowed to contain an oxide of a metal other than ytterbium, and the proportion of ytterbium in all metal atoms in the oxide is 80% or more.

A Faraday rotator and an optical isolator having a high transmittance and a high Verdet constant are provided. The optical isolator includes at least a Faraday rotator that rotates a polarization plane of incident light in a non-reciprocal manner, a polarizer disposed on a light incident side of the Faraday rotator, and an analyzer disposed on a light exit side of the Faraday rotator. The Faraday rotator is made of an oxide containing ytterbium oxide (Yb.sub.2O.sub.3), and is manufactured by a ceramic manufacturing process, wherein the oxide is allowed to contain an oxide of a metal other than ytterbium, and the proportion of ytterbium in all metal atoms in the oxide is 80% or more.

An apparatus having an asymmetric adjustable lens with a deformable optical element. The apparatus may also include one or more actuators coupled to a deformable element of the asymmetric adjustable lens in a direct-drive configuration such that (1) mechanical action of the one or more actuators applies force to the deformable optical element and (2) the force applied by the mechanical action of the one or more actuators changes an optical property of the asymmetric adjustable lens by deforming the deformable optical element. Various other devices, systems, and methods are also disclosed.

A high-quality crystalline film having less impurity of Si and the like and useful in semiconductor devices is provided. A crystalline film containing a crystalline metallic oxide including gallium as a main component, wherein the crystalline film includes a Si in a content of 2×10.sup.15 cm.sup.−3 or less.

A high-quality crystalline film having less impurity of Si and the like and useful in semiconductor devices is provided. A crystalline film containing a crystalline metallic oxide including gallium as a main component, wherein the crystalline film includes a Si in a content of 2×10.sup.15 cm.sup.−3 or less.

Provided is a semiconductor device, including at least: a semiconductor layer; and a gate electrode that is arranged directly or via another layer on the semiconductor layer, the semiconductor device being configured in such a manner as to cause a current to flow in the semiconductor layer at least in a first direction that is along with an interface between the semiconductor layer and the gate electrode, the semiconductor layer having a corundum structure, a direction of an m-axis in the semiconductor layer being the first direction.