Protein detection on biotin-derivatized polyallylamine by optical microring resonators.

Silicon optical microring resonators (MRRs) are sensitive devices that can be used for biosensing. We present a novel biosensing platform based on the application of polyelectrolyte (PE) layers on such MRRs. The top PE layer was covalently labeled with biotin to ensure binding sites for antibodies via a streptavidin-biotin binding scheme. Monitoring the shift in the microring resonance wavelength allows real-time, highly sensitive detection of the biomolecular interaction.

Mechano-optical wavelength tuning in a photonic crystal microcavity with sub-1 V drive voltage.

A micro-bimorph cantilever with self-aligned nanotips is monolithically integrated with a photonic crystal based device using optical and deep UV lithography techniques. Upon electrostatic actuation, the dielectric nanotips perturb the optical field, providing electromechano-optical modulation of light. Static tuning of the optical transmission spectra by more than 600 pm is measured with a sub-1 V drive voltage, resulting in a modulation as high as 21 dB. The observed strong electromechano-optical effect may find application in power efficient devices for optical communication networks, such as wavelength routing elements.

Micromechanically tuned ring resonator in silicon on insulator.

We demonstrate a monolithically integrated micromechano-optical device where the resonance wavelength of a silicon ring resonator is tuned by perturbing the evanescent field with an electrostatically actuated silicon nitride microcantilever. The resonance wavelength can be tuned over 125 pm.

First report of Vibrio cholerae infection from Andaman and Nicobar, India.

Out of 34 Stool Samples collected during an outbreak of diarrhoea, Vibrio cholerae 01 was isolated from 10 samples contrary to earlier reports that Shigella species was the only cause of diarrhoeal disease in Andaman & Nicobar Islands.