High-Power Free-Space Bulk Multiplexer for Satellite Communication Optical Ground Terminal

High throughput optical satellite communication (SATCOM) systems need to rely on effective and robust technology to enable wavelength-division multiplexing (WDM) in a commercially viable way. The main challenge to implement WDM in optical feeder links deals with the multiplexing of high power channels. Currently the levels of power required for...

Beam multiplexing for satellite communication optical feeder links

Optical satellite communication is growing fast and among various applications it requires higher throughput optical feeder links. Optical feeder links for satellite communication necessitate very high data throughput, up to 1 Terabit/s and beyond. Amongst several multiplexing strategies, dense wavelength division holds a key position to enable...

Design and characterization of the blazed holographic UV gratings for Tropomi

Optical components such as diffraction gratings are widely used in Space-flight satellites to analyse light properties from soft-X rays to Infra-Red. The diffraction gratings are one of the key optical components of space-flight instruments and have to exhibit very high optical performances. TROPOMI (Tropospheric Monitoring Instrument) is a...

A set of innovative immersed grating based spectrometer designs for METIS

We present innovative, immersed grating based optical designs for the SMO (Spectrograph Main Optics) module of the Mid-infrared E-ELT Imager and Spectrograph, METIS. The immersed grating allows a significant reduction of SMO volume compared to conventional echelle grating designs, because the diffraction takes place in high refractive index...

Ill-posed inverse problem in diffraction optics: Tolerance analysis of diffractive lenses and gratings

A method is proposed for the prediction of deviations of the phase polynomial coefficients of diffractive optical elements from their nominal values due to fabrication errors. This problem represents an ill-posed inverse problem in diffraction optics. Its solution is based on the regularization technique resulting in an approximate stable ...

The double monochromator geometric theory and compensation of aberrations

The light path function for the double monochromator is constructed, and the formulas of account of the members of its expanding in ascending power series adequate for the defocusing and the first order astigmatism aberrations are found. On the basis of results of the minimisation of obtained expressions the opportunity of construction of a...

Apparent motion produced by temporally modulated brightness contrast and assimilation

When regions containing a counterphasing sine-wave grating are presented side by side and in spatial and temporal quadrature phase, a transparent perception of motion results. This occurs even though none of the stimulus parts is moving. The two percepts of motion in these displays are in opposite directions, one analogous to brightness contrast...