A new design for an all optical flip flop is introduced. It is based on a nonlinear Distributed Bragg Reflector (DBR) semiconductor laser structure. The device does not require a holding beam. An optical gain medium confined between 2 Bragg reflectors forms the device. One of the Bragg reflectors is detuned from the other by making its average refractive index slightly higher, and it has a nega...

Free-space data center interconnects (wireless, optical) require a reflection mechanism to avoid obstacles/interference that can arise due concentrating signals in a plane consisting of source/destination nodes. A proper reflection mechanism above the communicating nodes (as in Fig. 1) enables a beam to depart the source, hit the reflector structure well above the source and destination, and he...

■ ■ In 1987 you started working on the idea of a photonic crystal. What made you consider such a problem? At that time, some papers had appeared suggesting it was possible to suppress spontaneous emission (SE). I think the first paper was by Dan Kleppner, an atomic physicist from MIT, who suggested putting an atom between two metal plates1. However, that covers only 50% of the SE, that is, it s...

In this paper the problem of synthesis of offset shaped single reflector antenna is considered. This problem has to be solved when a reflector antenna system is required to control the field amplitude and/or phase on the far-field or on the output aperture in the near-field. Achieving high efficiency is a very important objective of the design and shaped reflector antennas are used for that pur...

The generation of nodal cross sections and equivalence parameters for prismatic VHTR core components is discussed. For fuel-block cross section generation, a conventional single-block model with a reflective boundary condition is used. A one-dimensional fuel-reflector model is proposed for reflector cross section generation in order to accurately represent the significant neutron spectrum varia...

The light reflectors in the beetles Calloodes grayanus and Anoplognathus parvulus are examined. Contrasting multilayer reflectors are revealed. Calloodes grayanus appears a weak green colour, matching its background leaves, while A. parvulus is strongly metallic-gold coloured. The former reflection is diffuse, as the result of a structure causing scattering that overlies the multilayer reflecto...

Using a reflector insert, the original HM-3 lithotripter field at 20 kV was altered significantly with the peak positive pressure (p(+)) in the focal plane increased from 49 to 87 MPa while the -6 dB focal width decreased concomitantly from 11 to 4 mm. Using the original reflector, p(+) of 33 MPa with a -6 dB focal width of 18 mm were measured in a pre-focal plane 15-mm proximal to the lithotri...

We report on a 151-ks net exposure Suzaku observation of the narrow-line Seyfert 1 galaxy Mrk 335. The 0.5–40 keV spectrum contains a broad Fe line, a strong soft excess below about 2 keV and a Compton hump around 20–30 keV. We find that a model consisting of a power law and two reflectors provides the best fit to the time-averaged spectrum. In this model, an ionized, heavily blurred, inner ref...

The reflector used by an imaging atmospheric Cherenkov telescope (IACT) consists of a tessellated array of mirrors mounted on a large frame. This arrangement allows for a very large reflecting surface with sufficient optical quality for the implementation of the IACT technique at a moderate price. The main challenge presented by such a reflector is maintaining the optical quality, which depends...

Three compact and efficient designs are proposed to deliver an average irradiance of 50 mW/cm(2) with spatial uniformity well above 90% over a 25 mm(2) target area for photodynamic therapy of the oral cavity. The main goal is to produce uniform illumination on the target while limiting irradiation of healthy tissue, thus overcoming the need of shielding the whole oral cavity and greatly simplif...