Control of transverse mode spectrum of Novosibirsk free electron laser radiation

Novosibirsk Free Electron Laser—Facility Description and Recent Experiments

“…Another radiation-resistant material, high-resistivity silicon, has better mechanical characteristics and many technological processes can be applied to its treatment. These capabilities were used in the creation of a set of binary diffraction optical elements (DOEs) [12], [13]. That enabled splitting the laser beam into three beams, shaping of the laser beam into given volumes, transformation of laser beam modes, uniform illumination of a square area, and, finally, formation of beams with orbital angular momentum.…”

Control of transverse mode content and polarization structure of terahertz coherent beams

“…Недостатками таких устройств являются габаритные характеристики, а также относительная сложность технологического исполнения. В работах [5,7,8] приведены результаты исследования бинарных (двухуровневых) кремниевых дифракционных оптических элементов (ДОЭ), предназначенных для формирования одномодовых пучков терагерцового диапазона из освещающего пучка лазера на свободных электронах. Ранее ДОЭ оптического диапазона, cогласованные с поперечными модами лазерного излучения, были предложены в [9].…”

Investigation of the properties of a 3-level broadband antireflective structure on silicon by THz time-domain spectroscopy

“…To increase the amount of absorption, it is necessary to reduce losses associated with Fresnel reflection. For this, it was decided to create an antireflection coating on one side of the silicon substrate [3,4].…”

“…To provide broadband antireflection effect, on the one side of the substrate a 3-level structure has been realized by use of reactive ion etching (Bosch process) [3,5].…”