PLANCK is a project of the European Space Agency to be launched in February 2007 by an ArianeV rocket with the Herschel Space Observatory . It is designed for imaging the temperature and polarization anisotropies of the millimetre and submillimetre radiation over the whole sky with unprecedented sensitivity, accuracy and angular resolution using 9 frequency channels ranging between 25 and 1000 GHz. The main source at these frequencies is the Cosmic Microwave Background (CMB), i.e. the radiation emitted by the early universe when, about 300000 years old, ionised hydrogen recombined and became transparent from the visible to radio frequencies of the electromagnetic spectrum. The main goal of the PLANCK mission is to retrieve the main cosmological parameters of the Universe with accuracies of a few percent from the observation and analysis of random small contrast (10–4) features in the CMB. The angular power spectrum of the CMB anisotropies is a function of the fundamental cosmological parameters. A proper measurement of all the angular frequencies of the CMB is essential for an accurate interpretation of the data. In consequence the optical performances of Planck will directly impact the ability of retrieving theses parameters. Recent results of the Willkinson Microwave Anisotropy Probe (WMAP) mission show that polarization information of CMB radiation is very challenging, and that the precise measurement of the CMB could completely change the knowledge we have on our universe (). The focal plane assembly (FPA) of the PLANCK telescope is composed of two instruments. The High Frequency Instrument (HFI) of PLANCK is the most sensitive CMB experiment ever planned (). Together with the Low Frequency Instrument (LFI), this will make a unique tool to measure the full sky and to separate various components of its spectrum. This paper describes the main performances of the HFI beams and compares results obtained with 2 different softwares: GRASP8  and an home-made software developed at the Ireland National University of Maynooth . Specials attention will be paid to polarized beams (100, 143, 217, 353 GHz) and multimoded channels (545 and 857 GHz).
Optical design in the terahertz (THz) waveband can be challenging, especially for high-precision applications. In this
paper we summarise our experience with the quasi-optical design and subsequent performance of astronomical
telescopes designed to measure the faint temperature and polarisation properties of the Cosmic Microwave Background
Radiation, in particular QUaD<sup>1</sup>, the PLANCK Surveyor<sup>2</sup> and MBI<sup>3</sup>. These telescopes contain a range of quasi-optical
components including corrugated feed horns, on- and off-axis conic mirrors and lenses. Knowledge of their optical
performance and beam patterns is critical for understanding systematic effects in the reliable extraction of feeble
Although Physical Optics can be used to characterise electromagnetic systems to high accuracy, it is computationally
intensive at these frequencies and often not suitable for the initial design or preliminary analysis of large multi-element
optical systems. In general there is a lack of dedicated software tools for modelling the range of components and
propagation conditions encountered in typical systems and we have employed a variety of commercial and in-house
software packages for this task. We describe the techniques used, their predictions and the performance of the
telescopes that have been measured to-date.
The future ESA space mission Planck Surveyor mission will measure the Cosmic Microwave Background temperature and polarisation anisotropies in a frequency domain comprised between 30GHz and 1THz. On board two instruments, LFI based on HEMT technology and HFI using bolometric detectors. We present the optical solutions adopted for this mission, in particular the focal plane design of HFI, concept which has been applied already to other instruments such as the balloon borne experiment Archeops.
We present the latest results of our fast physical optics simulations of the ESA PLANCK HFI beams. The main beams of both polarized and non-polarized channels have been computed with account of broad frequency bands for the final design and positions of the HFI horns. Gaussian fitting parameters of the broadband beams have been presented. Beam polarization characteristics and horn defocusing effects have been studied.
Optical design in the terahertz (THz) waveband suffers from a lack of dedicated software tools for modelling the range of electromagnetic and quasi-optical propagation conditions encountered in typical systems. Optical engineers are forced to use packages written for very different wavelength systems and there is often a lack of confidence in the results because of possible inappropriate underlying physical models. In this paper we describe the analytical techniques and dedicated CAD software tools (MODAL) that we are developing for long-wavelength design and analysis in the THz waveband. Our basic approach to modelling long-wavelength propagation is the application of modal analysis appropriate to the problem under investigation. We have extended this to include the efficient description of common off-axis (tilted) components such as simple curved reflectors. In earlier research we have investigated the conditions under which approximate methods (ray tracing, paraxial modes) can provide extremely efficient and accurate solutions and situations where a more rigorous approach is required. As a rigorous model of electromagnetic wave propagation, physical optics can be used to characterize complete systems to high accuracy. However, the straightforward approach is computationally intensive and, therefore, not suitable for the initial design or preliminary analysis of large multi-element optical systems. In order to improve the computational efficiency of the usual PO approach we have developed fast physical optics software, initially for the analysis of the ESA PLANCK system. The MODAL code is modular and multi-platform, and different propagation models can be used within the same framework. Distributed parallel computing enables significant reduction of the time needed to perform the calculations. We present the new software and analyses of the QuaD and Herschel (HIFI) telescope systems.
Advances in technology of submicron semiconductor structures make it possible to de- velop a great variety of novel non-conventional Ohotoreceivers. Even if consideringthe classical effects only, one can see that various kinds of the effects could takeplace in the structures of that scale. The nature of the effect depends on relationsbetween the device active layer thickness a and the main physical lengths whichdescribe the relaxation processes in a semiconductor. For submicron structures, therelations