Which systems are ideal to obtain negative refraction with no absorption? Electromagnetically induced transparency (EIT) is a method to suppress absorption and make a material transparent to a field of a given frequency. Such a system has been discus
sed in [1]; however the main limitations for negative refraction introduced are the necessity of resonant electric and magnetic dipole transitions, and the necessity of very dense media. We suggest using frequency translators in a composite system that would provide negative refraction for a range of optical frequencies while attempting to overcome the limitations discussed above. In the process of using frequency translators, we also find composite systems that can be used for refractive index enhancement.
The presented results are obtained during the first steps taken in order to develop a setup and measurement procedures which allow to compare properties of diverse kinds of silicon photomultipliers. The response to low-intensity light was studied for
silicon photomultipliers produced by CPTA (Russia), Hamamatsu (Japan), ITC-irst (Italy) and SensL (Ireland).
Two different technologies are considered for the Beam Calorimeters of the ILC detector. Simulation studies of the performance have been done for a diamond-tungsten sandwich calorimeter and for a homogeneous heavy element crystal calorimeter with opt
ical fiber readout. Studies of the stability and the linearity of a polycrystalline diamond were done for the diamond-tungsten option. For the heavy crystal option the light yield reduction due to the wavelength shifting fiber readout was studied.
