Share Email Print
cover

Proceedings Paper

Tunable integrated optical filters based on sapphire microspheres and liquid crystals
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We present an integrated optical narrowband electrically tunable filter based on the whispering gallery modes of sapphire microspheres and double ion-exchanged channel BK7 glass waveguides. Tuning is provided by a liquid crystal infiltrated between the spheres and the glass substrate. By suitably choosing the radii of the spheres and of the circular apertures, upon which the spheres are positioned, arrays of different filters can be realized on the same substrate with a low cost industrial process. We evaluate the performance in terms of quality factor, mode spacing, and tuning range by comparing the numerical results obtained by the numerical finite element modeling approach and with the analytical approach of the Generalized Lorenz-Mie Theory for various design parameters. By reorienting the LC in an external electrical field, we demonstrate the tuning of the spectral response of the sapphire microsphere based filter. We find that the value of the mode spacing remains nearly unchanged for the different values of the applied electric field. An increase of the applied electric field strength, changes the refractive index of the liquid crystal, so that for a fixed geometry the mode spacing remains unchanged.

Paper Details

Date Published: 17 May 2010
PDF: 7 pages
Proc. SPIE 7719, Silicon Photonics and Photonic Integrated Circuits II, 77191E (17 May 2010); doi: 10.1117/12.855978
Show Author Affiliations
Giovanni Gilardi, Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (Italy)
Univ. degli Studi di Roma La Sapienza (Italy)
Hasan Yilmaz, Koç Univ. (Turkey)
Mohammed Sharif Murib, Koç Univ. (Turkey)
Rita Asquini, Univ. degli Studi di Roma La Sapienza (Italy)
Antonio d'Alessandro, Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (Italy)
Univ. degli Studi di Roma La Sapienza (Italy)
Ali Serpengüzel, Koç Univ. (Turkey)
Romeo Beccherelli, Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e Microsistemi (Italy)


Published in SPIE Proceedings Vol. 7719:
Silicon Photonics and Photonic Integrated Circuits II
Giancarlo Cesare Righini, Editor(s)

© SPIE. Terms of Use
Back to Top