Tens Of Beams Research Articles

Simplified design of optical elements for filled-aperture coherent beam combination.

A simplification strategy for segmented mirror splitters (SMS) used as beam combiners is presented. These devices are useful for compact beam division and the combination of linear and 2-D arrays. However, the standard design requires unique thin-film coating sections for each input beam; thus, potential for scaling to high beam-counts is limited due to manufacturing complexity. Taking advantage of the relative insensitivity of the beam combination process to amplitude variations, numerical techniques are used to optimize highly simplified designs with only one, two or three unique coatings. It is demonstrated that with correctly chosen coating reflectivities, the simplified optics are capable of high combination efficiency for several tens of beams. The performance of these optics as beam splitters in multicore fiber amplifier systems is analyzed, and inhomogeneous power distribution of the simplified designs is noted as a potential source of combining loss in such systems. These simplified designs may facilitate further scaling of filled-aperture coherently combined systems in linear array or 2-D array formats.

High-efficiency fiber grating for producing multiple beams of uniform intensity

In this paper, we propose a high-efficiency diffraction grating called a fiber grating, which is composed of many optical fibers arrayed as a monolayer. When a laser beam is irradiated perpendicularly onto the grating, the device can emit several tens of beams with uniform intensities over a wide angle. Crossed fiber gratings can produce 2-D spot arrays. The application in multiple imaging is demonstrated.

Laser-pumped molecular laser

The parameters of laser-pumped molecular lasers are investigated. It is established that the energy and tuning characteristics of an NH3 laser (Eg = 1.5 J, efficiency 20%, Pav = 20 W, radiation frequency tuning band 753–890 cm-1) are decisively influenced by the addition of N2. A focusing raster optical-pumping system has made it possible to obtain a specific lasing energy 12 J/liter. A CF4 laser with lasing energy 40 mJ operates in the 612–655 cm-1 band. Experiments on dissociation of the molecules CCl4 and UF6 were carried out with the aid of NH3 and CF4 lasers. The systems and methods of producing Raman lasers (RL) are presented. An effective RL amplifier on rotational transitions in compressed H2, which transforms tens of beams of Nd lasers into one coherent beam of the first Stokes component with λ ≅ 1.13 μm at an efficiencyup to 70%, is described.