Comparative study on diode-pumped continuous wave laser at 607  nm using differently doped Pr^3+:LiYF_4 crystals and wavelength tuning to 604  nm

Abstract

We comparatively study an InGaN laser-diode-pumped continuous-wave laser at ∼607 nm (σ polarization) using differently doped Pr:LiYF₄ single crystals. Maximum output power and slope efficiency at this wavelength were up to 209 mW and 47.1%, respectively, using a 0.2 at. % doped and 8 mm sample. Findlay-Clay analysis shows roundtrip losses, including reabsorption loss at this particular emission of about 1.2% using the 0.2 at. % doped sample, which is lower than that of samples with higher doping concentrations at 0.5 and 1 at. %. Using a 0.15 mm glass plate as a Fabry-Perot etalon, a maximum output power of 73 mW was achieved at ∼604 nm (π polarization) with slope efficiency of 17.2% for what is believed to be the highest result currently.

True-3D Accentuating of Grids and Streets in Urban Topographic Maps Enhances Human Object Location Memory

“…The distance was measured in pixels (px). In accordance with previous research [ 8 , 22 , 30 , 39 , 40 ], the location of a recalled POI was considered correct if it deviated no more than 40.27 px (0–1 cm) from the location of the object to be learned. An independent-measures t-test was applied to compare the means from the 2D- and 3D-GRID conditions.…”

“…In accordance with previous research [ 52 , 53 , 56 , 57 ], content highlighted in True-3D attracts and increases the user’s visual attention. An increased attention to the regular and orthogonal grid structures seems to further improve the chunking effect of grids that might lead to a more accurate object location memory (see also [ 32 – 35 , 39 , 40 ]).…”

“…In addition to grids, previous studies also reported effects of linear map elements on perception and memory, such as boundary lines, rivers or streets [ 16 , 30 , 31 , 40 , 66 ]. In contrast to grids, these elements represent content which is a fundamental part of the map theme.…”

“…It was shown that artificial, structuring elements, such as continuous grid lines, support the perception and recognition of object locations in images [ 32 – 35 ]. Grids, which are traditional cartographic elements used to locate represented map objects or to define their coordinates [ 36 – 38 ], also increase performance in map-based object location memory tasks [ 30 , 39 , 40 ]. Of interest is that the effects of grids interact with the complexity and geographic context represented in the topographic base map.…”

“…Two studies are conducted to explore the True-3D effects of grids (Study 1: 3D vs. 2D Grids) and streets (Study 2: 3D vs. 2D Streets). Following the results of previous studies [ 8 , 19 , 30 , 40 ], it is assumed that the systematic structure of grids and the pattern of the streets divide the map surface into information aggregates, which enhances the spatial memory performance. The 3D depth effect (grid / street layer appears closer to the viewer) is expected to guide the user’s attention to the graphically emphasized orientation pattern provided by the grids and lines [ 50 – 57 ], and, thus, to support the user’s object location memory.…”