A Multifunctional Combination Incubator

Energy, precision, and multi-functionality have become primary considerations in incubators. For example, if a part of an apparatus must be insulated, while other parts do not, then the specific part can be placed in the multi-functional incubator proposed in this paper to avoid wasting energy. The proposed incubator is composed of various parts including a platform, which is provided for debugging parts to meet the working accuracy of parts. The light windows are adjustable in height to accommodate different heights of light. The incubator is black to prevent stray light in optical experiments. This design can not only insulate but also debug optical or non-optical parts according working accuracy of parts. In this paper, an example incubator is used for an optical experiment was given and the incubator was optimized several times. The temperature fluctuations of the box of the third optimized incubator reached 0.045∘C. To reduce the temperature fluctuations, the relationship between the ambient and target temperature as well as the temperature fluctuations of the box were analyzed, and a formula was proposed. A further experiment provided evidence for this relationship. Based on the formula, the SLITA (small optimized incubator placed in large optimized incubator with the same target temperature) method for improving insulation accuracy was further proposed, and an incubator was designed using this method. The temperature fluctuations were 0.000014∘C by simulation, which was reduced 98.6% compared to previous incubators.

Efficient Hogel-Based Hologram Synthesis Method for Holographic Stereogram Printing

With the development of the holographic printer, printing synthetic hologram requires smaller holographic element (hogel) size to improve spatial resolution of the reconstruction. On the contrary, a larger hogel size affords higher angular resolution, but it leads to a lower lateral resolution and there exists a trade-off problem. In this paper, a hologram synthesis method based on three-dimensional (3D) rendering of computer-generated holographic stereogram (HS) is proposed to limit the spatial-angular trade-off problem. The perspectives of the 3D scene are captured by re-centering the camera method and transformed into parallax-related images by a proposed pixel re-arrangement algorithm for holographic printing. Unlike the conventional approaches, the proposed algorithm not only improves the angular resolution of the reconstruction while maintaining the hogel size fixed, but also keeps the spatial resolution without degradation. The effectiveness of the proposed method is verified by numerical simulation and an optical experiment.

An Airborne Offner Imaging Hyperspectrometer with Radially-Fastened Primary Elements

We propose a new layout for the Offner imaging hyperspectrometer that is utilized onboard small space vehicles. The layout is based on a method of adjusting the adaptive temperature-dependent optical scheme by moving just two coaxial optical components located inside the hyperspectrometer. We present the results of modeling for a temperature range of −40 to +45 °C and an optical experiment using a heat and cold chamber for the range of 12 to 40 °C, proving the basic functionality of the proposed layout. Based on simulation results, the new layout is supposed to allow the hyperspectrometer to operate in a temperature range of −40 to +45 °C without its optical characteristics deteriorating, thus making it suitable for work onboard space or stratospheric vehicles.

ОBSERVATION OF FERMI-PASTA-ULAM-TSINGOU RECURRENCE IN OPTICAL EXPERIMENT

Recently P.G. Grinevich and P.M. Santini suggested simple approximate formulas for solving periodic Cauchy problem for the focusing Nonlnear Schrodinger Equation (NLS) under assumption that one starts from a small perturbation of the unstable condensate and the number of unstable modes is not too large. With the help of these results, optical experiments in photorefractive crystal where conducted, in which the second and third return of anomalous waves was observed. A good agreement between the experimental data and the predictions made on the basis of the NLS theory was obtained. P.G. Grinevich was supported by the Russian Science Foundation grant No. 18-11-00316.