During everyday life we move around busy environments and encounter a range of obstacles, such as a narrow aperture forcing us to rotate our shoulders in order to pass through. In typically developing individuals the decision to rotate the shoulders is body scaled and this movement adaptation is temporally and spatially tailored to the size of the aperture. This is done effortlessly although it...

An improved range-Doppler algorithm (RDA) is proposed to reconstruct images from synthetic aperture radar (SAR) data received at high squint angles. At a higher squint angle, a larger synthetic aperture is required to receive sufficient amount of data for image reconstruction, and the range migration also becomes more serious, which demands more computational load and larger memory size. The pr...

We report astonishingly high transmission enhancement factors through a subwavelength aperture at microwave frequencies by placing connected split ring resonators in the vicinity of the aperture. We carried out numerical simulations that are consistent with our experimental conclusions. We experimentally show higher than 70,000-fold extraordinary transmission through a deep subwavelength apertu...

A theory of diffraction-limited spot size is developed for infinity-corrected microscope optics. Previously reported formulae were originally derived using a single-lens system. In addition, the previously reported relationship between f -number and numerical aperture assumed a paraxial approximation and was limited to air-immersion lenses. Here, a new relationship between f -number and numeric...

There exists a fundamental trade-off between the spectral resolution and the efficiency or throughput for all optical spectrometers. The primary factors affecting the spectral resolution and throughput of an optical spectrometer are the size of the entrance aperture and the optical power of the focusing element. So far, the collective optimization of the above mentioned has proven difficult. He...

We try to improve the accuracy of eccentric photorefraction by taking more information into account than just the size and tilt of the crescent. Based on Gaussian optics and the assumption of an isotropic scattering retina, a theoretical analysis of the light-intensity distribution in the pupils of astigmatic eyes is presented. The method is applied to different photorefractor setups (point lig...

Fig. 2 shows the total electric polarisability x(-d) against aperture depth for four different cases which have the same total area. As the individual aperture size becomes smaller, so does the total polarisability. Fig. 3 illustrates the potential distributions for cases (iii) and (iv) of Fig. 2 when d = 0. It is seen that the potentials retain ahnost plateau shapes within the apertures, while...

Bowtie aperture antennas are known to generate sub-diffraction limited optical spots in the visible and near-infrared frequencies, which can be applied to many areas. Regular bowtie apertures fabricated by FIB suffer from tapered sidewall and rounded corner, which degrade its optical enhancement and localization. In this work, a new fabrication method is demonstrated to manufacture bowtie apert...

We have developed a class of aperture coding schemes for Remote Raman Spectrometers (RRS) that remove the traditional trade-off between throughput and spectral resolution. As a result, the size of the remote interrogation region can be driven by operational, rather than optical considerations. In this paper we present the design of our coded-aperture standoff spectroscopy system as well as expe...

The fractional transmission as a function of wavelength for stellar objects is measured for clear apertures by comparing count rates through small apertures to open aperture count rates in STIS first order modes. Because OTA "breathing" causes the throughput of the smallest apertures to vary on short time scales, the best estimate of the aperture throughputs is a theoretical model that is based...