OPTICAL SYSTEM DESIGN OF THE DETECTOR FOR SOLAR TERAHERTZ EMISSION MEASUREMENTS

The objectives and scientific tasks of the planned space experiment “Solntse-Terahertz” to be performed onboard the ISS Russian Segment are briefly described in the paper. In particular, the aim of the experiment is to study uninvestigated solar electromagnetic emission in the terahertz domain, in ~ 1012 – 1013 Hz (300-30 µm) frequency range. It is expected to obtain new data on solar active region emission including solar flare emission. These data are necessary to clarify the nature of solar activity and construct physical model of charged particle acceleration in active regions during solar flares and other astrophysical objects. We focus on the telescope optical system design and evaluation of main characteristics of this system. Results of simulations and comparison with the experimental verification of obtained characteristics are presented. A close correlation of the estimations and experimental results was obtained. As a result, main parameters of the telescope optical system of experimental hardware “Solntse-Terahertz” were determined. Key words: Sun, solar flares, terahertz emission, optical system.

Light detection and ranging (LIDAR) laser altimeter for the Martian Moons Exploration (MMX) spacecraft

An altimeter is a critical instrument in planetary missions, for both safe operations and science activities. We present required specifications and link budget calculations for light detection and ranging (LIDAR) onboard the Martian Moons Exploration (MMX) spacecraft. During the mission phase, this LIDAR will continuously measure the distance between the spacecraft and its target. The time-series distance provides important diagnostic information for safe spacecraft operations and important information for geomorphological studies. Because MMX is a sample return mission, its LIDAR must accommodate physical disturbances on the Martian satellite surface. This resulted in changes to the optical system design. Graphical abstract

Large-scale two-photon calcium imaging in freely moving mice

We developed a miniaturized two-photon microscope (MINI2P) for fast, high-resolution, multiplane calcium imaging of over 1,000 neurons at a time in freely moving mice. With a microscope weight below 3g and a highly flexible connection cable, MINI2P allowed imaging to proceed with no impediment of behavior in half-hour free-foraging trials compared to untethered, unimplanted animals. The improved cell yield was achieved through a new optical system design featuring an enlarged field of view (FOV) and a new micro-tunable lens with increased z-scanning range and speed that allowed for fast and stable imaging of multiple, interleaved planes as well as 3D functional imaging. A novel technique for successive imaging across multiple, adjacent FOVs enabled recordings from more than 10,000 neurons in the same animal. Large-scale proof-of-principle data were obtained from cell populations in visual cortex, medial entorhinal cortex, and hippocampus, revealing spatial tuning of cells in all areas, including visual cortex.

Development of micromirror-based laser line generator

A laser line generator projects a straight line on an object and is widely used for alignment, identification, barcode reading, etc. Conventional laser line generators make use of cylindrical and Powell lenses that convert a laser beam spot into a line. Because of a fixed fan angle, however, the length and brightness of the generated line depends on the working distance between the laser module and object. In this project, using the optical system design software Zemax and engineering CAD software Solidworks, a micromirror based laser line generator is designed and fabricated. The performance of the fabricated micromirror based laser line generator is tested and compared with the performance of a conventional laser line generator. The results show that the length and brightness of image line can be kept constant by the designed generator.

Development of micromirror-based laser line generator

A laser line generator projects a straight line on an object and is widely used for alignment, identification, barcode reading, etc. Conventional laser line generators make use of cylindrical and Powell lenses that convert a laser beam spot into a line. Because of a fixed fan angle, however, the length and brightness of the generated line depends on the working distance between the laser module and object. In this project, using the optical system design software Zemax and engineering CAD software Solidworks, a micromirror based laser line generator is designed and fabricated. The performance of the fabricated micromirror based laser line generator is tested and compared with the performance of a conventional laser line generator. The results show that the length and brightness of image line can be kept constant by the designed generator.