Highly sensitive sensor based on an ultra-high-Q Mach-Zehnder interferometer-coup led microring
2009 (English)In: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, Vol. 26, no 3, 511-516 p.Article in journal (Refereed) Published
A high-Q Mach-Zehnder interferometer (MZI)-coupled microring is presented for optical sensing with high sensitivity and a large measurement range. By optimizing the length difference, between the two arms of the MZI coupler, the MZI-coupled microring with a high-Q factor and high extinction ratio is obtained. In the present example, the Q factor of the designed silicon-nanowire-based microring is as high as 1.8 x 10(5) when the silicon nanowire has a propagation loss L=2 dB/cm. Due to this high-Q factor, the sensitivity for the change Delta n of the effective refractive index is about 10(-5)-10(-6) by measuring the shift of the resonant wavelength. Because of the wavelength dependence of the coupling ratio of the MZI coupler, it is possible to have only one resonant wavelength with a high extinction ratio in a very large wavelength span [i.e., the quasi-free spectral range of the MZI-coupler microring], which offers a very large measurement range covering the refractive index change
Place, publisher, year, edition, pages
2009. Vol. 26, no 3, 511-516 p.
resonator, silicon, microcavities
IdentifiersURN: urn:nbn:se:kth:diva-18296ISI: 000264593400019OAI: oai:DiVA.org:kth-18296DiVA: diva2:336342
QC 201005252010-08-052010-08-052013-11-19Bibliographically approved