Millisecond Photon Lifetime in a Slow-Light Microcavity.

Optical microcavities with ultralong photon storage times are of central importance for integrated nanophotonics. To date, record quality (Q) factors up to 10^{11} have been measured in millimetric-size single-crystal whispering-gallery-mode (WGM) resonators, and 10^{10} in silica or glass microresonators. We show that, by introducing slow-light effects in an active WGM microresonator, it is possible to enhance the photon lifetime by several orders of magnitude, thus circumventing both fabrication imperfections and residual absorption.

Tailoring of the free spectral range and geometrical cavity dispersion of a microsphere by a coating layer.

The modal dispersion of a whispering gallery mode (WGM) resonator is a very important parameter for use in all nonlinear optics applications. In order to tailor the WGM modal dispersion of a microsphere, we have coated a silica microsphere with a high-refractive-index coating in order to study its effect on the WGM modal dispersion. We used Er(3+) ions as a probe for a modal dispersion assessment.

Controling the coupling properties of active ultrahigh-Q WGM microcavities from undercoupling to selective amplification.

Ultrahigh-quality (Q) factor microresonators have a lot of applications in the photonics domain ranging from low-threshold nonlinear optics to integrated optical sensors. Glass-based whispering gallery mode (WGM) microresonators are easy to produce by melting techniques, however they suffer from surface contamination which limits their long-term quality factor to a few 10(8). Here we show that an optical gain provided by erbium ions can compensate for residual losses.

About the role of phase matching between a coated microsphere and a tapered fiber: experimental study.

Coatings of spherical optical microresonators are widely employed for different applications. Here the effect of the thickness of a homogeneous coating layer on the coupling of light from a tapered fiber to a coated microsphere has been studied. Spherical silica microresonators were coated using a 70SiO(2)- 30HfO(2) glass doped with 0.

High-gain wavelength-selective amplification and cavity ring down spectroscopy in a fluoride glass erbium-doped microsphere.

We experimentally demonstrate a compact optical amplifier consisting of a rare-earth-doped whispering-gallery-mode microsphere coupled via a tapered fiber. A gain up to 20 dB is reported in an erbium-doped fluoride glass microsphere 135 μm in diameter. Below the amplification regime, the optical gain is used to compensate for unavoidable losses due to surface contamination or scattering.