Journal Article

LEKIDs as mm-Wave Polarisation Analysers: Fabrication, Test Bench and Early Results

Monfardini, A., Moric, I., Smoot, G. F., Bleurvacq, N., Calvo, M., Cammilleri, D., Decourcelle, T., Prêle, D., Bélier, B., Piat, M., Tartari, A.

2016

Overview

We have demonstrated in an earlier paper that LEKIDs can be used in a polarisation selective way in a filled array configuration. A polarised response can be achieved by means of thick Nb polarising grids lithographed on the rear side of a 300 microns silicon wafer, on which Al resonators have been previously patterned. In the most interesting scheme that we have investigated, a unit cell formed by 4 pixels (2 by 2) responds simultaneously to two orthogonal (cartesian) polarisation states. To assess the effectiveness of this detection scheme, we have fabricated a first generation of devices (9 small arrays, 20–25 pixels each, on a 4 ″ Silicon wafer) by using a double-sided mask aligner suitable for a precise positioning of the individual grids in correspondence of each resonator’s meander, for the different LEKID geometries. We describe here the realisation of these first devices. The construction of a dedicated polarimetric test bench is also described in this contribution, together with the first characterisation results. We consider this activity as a first and necessary step to evaluate the polarisation purity attainable with polarisation-sensitive pixels whose size is comparable to the wavelength. This is a fundamental information to drive further studies.

• Publisher: Springer US
• Subject: Characterization and Evaluation of Materials / Condensed Matter Physics / Magnetic Materials / Magnetism / Physics / Physics and Astronomy