Spheric lens designed by nonlinear phase fitting method is proposed to duplicate the performance of logarithmic axicon, which can obtain a beam with long-focal-depth, small focal spot and side lobe.
Numerical results show when an appropriate rotational symmetric polarization pupil mask is used as an apodizer in the optical imaging system, it not only can effectively achieve the continuously focal shift in a small range and extend focal depth of the optimized system, but also can evidently increase the transverse resolution of the optimized system at the genuine focal plane.
Thus if the core's diameter is smaller than our effective focal depth (400 nm), then its visibility could be obscured by points above and below it.
The expected acceleration amplitude of the earthquake is forcefully related to the focal depth of small to moderate magnitude earthquakes in a region close to the source (Spyrakos et al. 2008; Hall et al. 1995).
According to the F-net web-site (NIED, www.fnet.bosai.go.jp), errors in hypocentral location in the moment tensor analysis are equal or smaller than those in the unified hypocenter catalogue, hence, the errors in epicenter and focal depth are smaller than 9 km and 10 km, respectively.
In the catalogue, errors in epicenter and focal depth are smaller than about 0.1 degree and 10 km, respectively (Japan Meteorological Agency, 1998).
The b-value is a tectonic parameter which indicates a measure of the relative abundance of greater to smaller earthquakes, and the stress and material conditions in the focal depth (Mogi, 1962; Scholz, 1968).
The ratio of the average focal depth to the Moho depth is approximately 0.3.
The problem had been that it was difficult to adjust the focal depth between the two cameras while filming.
Many focusing properties, such as the actual focal depth and relative focal depth on the axial plane, together with the focal spot size and diffraction efficiency on the real focal plane are characterized.
Our analysis indicates that the general focal length function is valid in designing CBCMs with larger extended focal depth.
