Utsunomiya University

About: Utsunomiya University is a education organization based out in Utsunomiya, Japan. It is known for research contribution in the topics: Laser & Holography. The organization has 4139 authors who have published 6812 publications receiving 91975 citations. The organization is also known as: Utsunomiya daigaku.

Measurement of mean thickness of transparent samples using simultaneous phase shifting interferometry with four interferograms.

Abstract: In this research a novel interferometric system is reported, which allows the generation of four simultaneous interferograms with phase shifts of π/2 The system consists of three coupled interferometers: a rectangular Sagnac interferometer which generates a primary pattern with crossed circular polarizations, coupled to two Michelson interferometers which operate as a multiplexing system, and generating replicas of the primary pattern The two coupled Michelson interferometers generate four patterns retaining their polarization properties, which allow independent phase shifts by placing a linear polarizer over each pattern, thereby, four interferograms with relative phase shifts of π/2 are obtained The optical phase is calculated using the well-known four-step algorithm With knowledge of the optical phase, different properties of the samples can be calculated or analyzed; in this case, by knowing the mean refractive index, we can calculate the mean thickness of test objects The results obtained for static transparent samples are presented The capability of the system to analyze dynamic events is shown when results for the calculation of a temperature field of a heat flow are presented

Two-color pump-probe interferometry of ultra-fast light-matter interaction.

Abstract: Two-color side-view probing of light-matter interaction from minute focal volume of a tightly focused fs-laser pump pulse reveals charge dynamics with high 0.9 μm optical resolution and approximately ~45fs temporal resolution defined by pulse duration. Use of two colors is advantageous for probing optically excited plasma regions with different density. Holographical digital focusing and spatial filtering were implemented to obtain the same resolution images for subsequent Fourier analysis. Fast plasma density decay with time constant ~150 fs was resolved and is consistent with self-trapping. Potential applications of an optical control over light-induced defects with deep-sub-wavelength resolution is discussed.

Intergeneric coaggregations among Oligotropha carboxidovorans and Acinetobacter species present in activated sludge.

Abstract: The coaggregation traits of two pairs of sewage sludge bacteria were tested and characterized. Oligotropha carboxidovorans S23 coaggregated with two strains of the genus Acinetobacter viz. Acinetobacter junii S33 (56%) and Acinetobacter johnsonii S35 (99%). Coaggregates of O. carboxidovorans S23 and A. junii S33 were small (20–40 μm), weak and susceptible to EDTA and a commercial protease (Actinase E). Actinase/periodate pretreatment of the partners prior to coaggregation revealed that interaction in this case was mediated by protein surface components. Coaggregates of O. carboxidovorans S23 and A. johnsonii S35 were large (above 100 μm), strong and not deflocculated by EDTA or Actinase E. Only periodate pretreatment of A. johnsonii S35 prevented this coaggregation indicating a role for a carbohydrate-containing moiety without the involvement of protein components. The potential mechanisms and strength of bacterial coaggregations seem to be pair dependent.