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2022 (English)In: Optical Materials Express, E-ISSN 2159-3930, Vol. 12, no 6, p. 2181-2198Article in journal (Refereed) Published
Abstract [en]
Low-power and compact phase shifters are crucial for large photonic circuits, both to cope with variability and to create programmable waveguide circuits scaling to thousands of tuning elements. This work demonstrates a liquid crystal phase shifter where a lateral silicon electrode "rail" on one side of the waveguide core. Using this architecture, a strong quasi-static electric field Eactuation can be applied over the gap, which is filled with liquid crystal cladding material, with modest voltages. Because the mode is largely confined in the waveguide, optical losses are limited, compared to earlier experiments with slot waveguides. The liquid crystal is deposited locally on three different device variations using inkjet printing. The local deposition avoids unwanted interference of the liquid crystal with other optical components such as grating couplers. Measurements show similar trends as simulations of the liquid crystal orientations. For one device with a length of 50∼µm, a phase shift of almost 0.9π is shown at 10∼VRMS. We also discuss the challenges with this first demonstration of this phase shifter geometry using a silicon side-rail as an electrode.
Place, publisher, year, edition, pages
Optica Publishing Group, 2022
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:kth:diva-315255 (URN)10.1364/OME.457589 (DOI)000810930800001 ()2-s2.0-85130602076 (Scopus ID)
Note
QC 20220630
2022-06-302022-06-302024-09-04Bibliographically approved