We report magnetic field tuning of the structure and Whispering Gallery Mode lasing from ferromagnetic nematic liquid crystal micro-droplets. Microlasers were prepared by dispersing a nematic liquid crystal, containing magnetic nanoparticles and fluorescent dye, in a glycerol-lecithin matrix. The droplets exhibit radial director structure, which shows elastic distortion at a very low external m...

We report what is to our knowledge the first observation of a subpicosecond terahertz (THz) pulse propagating as a superposition of the whispering-gallery modes (WGMs) of a dielectric cylinder. The WGM THz pulses are coupled into and out of a 5-mm-diameter silicon cylinder via a 100-mum -thick, single-mode silicon slab waveguide. We observed two round-trip cylindrical cavity pulses from this co...

Identifying the mode numbers in whispering-gallery mode resonators (WGMRs) is important for tailoring them to experimental needs. Here we report on a novel experimental mode analysis technique based on the combination of frequency analysis and far-field imaging for high mode numbers of large WGMRs. The radial mode numbers q and the angular mode numbers p = ℓ-m are identified and labeled via far...

The spectral shift response of optical whispering-gallery modes due to the adsorption and desorption of water molecules into a SiO2 nano-coating is investigated. This coating is applied to a silica microsphere and optical-shift measurements are made at a very low humidity level (<10%). The micro-optical coupling system is incorporated into a sealed vacuum chamber for controlled humidity testing...

background: whispering gallery modes (wgm) biosensors are ultrasensitive systems that can measure amount of adsorbed layer onto the micro-cavity surface. they have many applications including protein, peptide growth, dna and bacteria detection, molecular properties measurements and specific interaction and drug table recognitions due to their high sensitivity, compact size and label free sensin...