InAs/GaSb Superlattice Based Mid-Infrared Interband Cascade Photodetectors Grown on Both Native GaSb and Lattice-Mismatched GaAs Substrates

Electrical and optical properties of interband cascade infrared photodetectors with InAs/GaSb type-II superlattice absorbers are investigated in this work. We compare the detection parameters of detectors grown on the native GaSb substrate and lattice-mismatched GaAs substrate and seek solutions to enhance device performance, specifically with using an optical immersion. The detectors grown on GaAs have better detection parameters at room temperature, but at lower temperatures the misfit dislocations become more important and detectors grown on GaSb become better.

Оптическое просветление кожи человека in vivo рядом моносахаридов

We present the results of in vivo optical immersion clearing of human skin by aqueous solutions of some immersion agents (ribose, glucose, and fructose monosaccharides and glycerol), obtained using optical coherence tomography (OCT). To assess the efficiency of optical clearing, we determined the values of the rate of change of the light scattering coefficient, obtained using the averaged A-scan of the OCT signal in the derma section at a depth of 350–700 μm. A good correlation was observed between the rate of change of the light scattering coefficient and the potential of the optical clearing. Using complex molecular simulation of the interaction of a number of immersion clearing agents with collagen mimetic peptide (GPH)_3 using classical molecular dynamics and quantum chemistry, we found correlations between the efficiency of optical clearing and the energy of intermolecular interaction of cleaning agents with a fragment of collagen peptide.

Chromospheric telescope of Baikal Astrophysical Observatory. New light

A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at the Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a 36×24 mm detector (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and new calcite and quartz crystal plates were made and installed instead of damaged ones in the Hα birefringent filter (BF), manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and prefilter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Hα line core and wing.

Chromospheric telescope of Baikal Astrophysical Observatory. New light

A chromospheric telescope is an important instrument for synoptic observations and solar research. After several decades of observations with the chromospheric telescope at Baikal Astrophysical Observatory, a need arose to improve the characteristics of this telescope and filter. A new reimaging lens to produce full-disk solar images 18 mm in diameter at the CCD camera Hamamatsu C-124 with a detector 36×24 mm (4000×2672 pixels) was designed and manufactured to replace the out-of-operation 50×50 mm Princeton Instruments camera. A contrast interference blocking filter and a new Iceland spar and quartz crystal plates instead of damaged ones were made and installed in the Hα birefringent filter (BF), manufactured by Bernhard Hallе Nachfl. The optical immersion in the filter was changed. All telescope optics was cleaned and adjusted. We describe for the first time the design features and their related BF passband tuning. The wavefront interferograms of optical elements and telescope as a whole show that the wavefront distortion of the optical path is within 0.25 λ. The BF and pre-filter spectral parameters provide high-contrast monochromatic images. Besides, we give examples of solar chromospheric images in the Ha line core and wing.

ALTERATIONS IN AUTOFLUORESCENCE SIGNAL FROM RAT SKIN EX VIVO UNDER OPTICAL IMMERSION CLEARING

For the first time, the changes in autofluorescence spectra of ex vivo rat skin have been experimentally investigated using the combination of fluorescence spectroscopy and optical immersion clearing. The glucose, glycerol and propylene glycol solutions were used as clearing agents. The optical clearing was performed from the dermal side of skin imitating the in vivo injection of clearing agent under the dermal layers. In this contribution, the common properties of autofluorescence variation during optical immersion clearing were determined. The tendency of autofluorescence signal to decrease with reduction of scattering in tissue was noticed and discussed in detail. However, the differences in the shape of spectral curves under application of different clearing agents showed that optical clearing affects the autofluorescence properties of tissue differently depending on the type of clearing liquid. The results obtained are useful for the understanding of tissue optical clearing mechanisms and for improving techniques such as fluorescence spectroscopy.