We compared BDFAs directly pumped with 1195 nm single-mode semiconductor laser(s) to 915 nm multimode laser via YDF mode/wavelength conversion stage. We demonstrated that 915/1150 nm pumping have superior performance and lower power consumption compared to 1195 nm.

We report BDFA with >20 dB gain over 1255-1355 nm bandwidth (17.6 THz) with maximum gain of 29.3 dB and corresponding NF of 4.6 dB (λ=1300 nm, Pin=-20 dBm). The BDFA has electrical power consumption of 8.1-9.6 W over 20-70 °C.

We present the first field-deployable hollow-core-fiber (HCF) cable and successfully demonstrate an error-free transmission of direct-detection 10Gb/s DWDM signals over a 3.1km cascaded HCF cable link, enabling 31% latency reduction compared to solid-core-fiber cable.

Advances in hollow-core fibers employing Perturbed Resonance for Improved Single Modedness (PRISM) with higher-order mode suppression and polarization maintaining behavior are discussed.

Based on the recently-introduced Surface Nanoscale Axial Photonics (SNAP) platform, we demonstrate a chain of 30 coupled SNAP microresonators spaced by 50 micron along an optical fiber, which is fabricated with the precision of 0.7 angstrom and a standard deviation of 0.12 angstrom in effective microresonator radius. To the best of our knowledge, this result surpasses those achieved in other super-low-loss photonic technologies developed to date by two orders of magnitude. The chain exhibits bandgaps in both the discrete and continuous spectrum in excellent agreement with theory. The developed method enables robust fabrication of SNAP devices with sub-angstrom precision.

We perform detailed measurements of the higher-order-mode content of a low-loss, hollow-core, photonic-bandgap fiber. Mode content is characterized using Spatially and Spectrally resolved (S2) imaging, revealing a variety of phenomena. Discrete mode scattering to core-guided modes are measured at small relative group-delays. At large group delays a continuum of surface modes and core-guided modes can be observed. The LP11 mode is observed to split into four different group delays with different orientations, with the relative orientations preserved as the mode propagates through the fiber. Cutback measurements allow for quantification of the loss of different individual modes. The behavior of the modes in the low loss region of the fiber is compared to that in a high loss region of the fiber. Finally, a new measurement technique is introduced, the sliding-window Fourier transform of high-resolution transmission spectra of hollow-core fibers, which displays the dependence of HOM content on both wavelength and group delay. This measurement is used to illustrate the HOM content as function of coil diameter.

We report the first experimental demonstration of coupled identical super-high Q-factor bottle microresonators formed by periodic nanoscale variation of the optical fiber radius. The Q-factor of the fabricated microresonator series exceeds 107.

We introduce multiple series of uncoupled and coupled surface nanoscale axial photonics (SNAP) microresonators along the 30 micron diameter germanium-doped photosensitive silica optical fiber and demonstrate their permanent trimming and temporary tuning with a CO2 laser and a wire heater. Hydrogen loading allows us to increase the introduced variation of the effective fiber radius by an order of magnitude compared to the unloaded case, i.e., to around 5 nm. It is demonstrated that the CO2 laser annealing of the fabricated microresonator chain can be used to modify the fiber radius variation. Depending on the CO2 laser beam power, the microresonator effective radius variation can be increased in depth up to the factor of two or completely erased. In addition, we demonstrate temporary tuning of a microresonator chain with a wire heater.

Recently introduced surface nanoscale axial photonics (SNAP) makes it possible to fabricate high-Q-factor microresonators and other photonic microdevices by dramatically small deformation of the optical fiber surface. To become a practical and robust technology, the SNAP platform requires methods enabling reproducible modification of the optical fiber radius at nanoscale. In this Letter, we demonstrate superaccurate fabrication of high-Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index using CO2 laser and UV excimer laser beam exposures. The achieved fabrication accuracy is better than 2 Å in variation of the effective fiber radius.

We demonstrate super-accurate fabrication of high Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index. The achieved fabrication accuracy is better than 2 angstroms in variation of the effective fiber radius.

An optical resonator is often called fully tunable if its tunable range exceeds the spectral interval that contains the resonances at all the characteristic modes of this resonator. For the high Q-factor spheroidal and toroidal microresonators, this interval coincides with the azimuthal free spectral range. In this Letter, we demonstrate the first mechanically fully tunable spheroidal microresonator created of a silica microbubble having a 100 micron order radius and a micron order wall thickness. The tunable bandwidth of this resonator is more than two times greater than its azimuthal free spectral range.

We demonstrate a technique for simultaneous drawing, tapering, and coiling of a silica optical fiber that is locally heated by a CO2 laser. It allows us to fabricate coils of silica fibers and microfibers with diameters ranging from ∼100μm down to less than a micron. As an application, we demonstrate an evanescent coiled fiber refractometric sensor comprising 15cm of standard single mode optical fiber. The dimension of this sensor is only 3mm×3mm×4mm and its sensitivity in the aqueous environment is estimated as ∼160nm/RIU.

We create silica microbubbles along a microcapillary with the CO2 laser heating and demonstrate the first optical microbubble resonator. It has 370 micron diameter, 2 micron wall thickness, and Q-factor exceeding 5·105.

An optical resonator is often called fully tunable if its tunable range exceeds the spectral interval that contains the resonances at all the characteristic modes of this resonator. For high-Q-factor spheroidal and toroidal microresonators, this interval coincides with the azimuthal free spectral range (FSR). In this Letter, we demonstrate what we believe to be the first mechanically fully tunable spheroidal microresonator created of a silica microbubble having a 100microm order radius and 1microm order wall thickness. The tunable bandwidth of this resonator is more than two times greater than its azimuthal FSR.

We demonstrate a robust double-capillary microfluidic ring resonator optical sensor imbedded into a solid polymer matrix. The device is capable of compensating the temperature and pressure variations and can be generalized to a multi-capillary lab-on-a-chip.

We demonstrate, for the first time to our knowledge, a multi-turn microfiber coil resonator. It is wrapped onto an optical rod in a liquid medium having the refractive index equal to that of the rod.

We demonstrate a robust and highly responsive optical microsensor, which probes the refractive index of liquids flowing along a ~ 100 mum radius channel formed in a polymer matrix. Sensing is based on measurement of the transmission spectrum of the whispering gallery modes, which are excited across the liquid channel by an optical microfiber imbedded into the polymer. The achieved sensitivity is 800 nm/RIU. Potentially, it is straightforward to assemble the sensing elements of this type into a lab-on-the-chip imbedded in a solidified optical material.

A thin dielectric waveguide with a subwavelength diameter can exhibit very small transmission loss only if its diameter is greater than a threshold value, while for smaller diameters, waveguide loss grows dramatically. The threshold diameter of transition between these waveguiding and nonwaveguiding regimes is primarily determined by the wavelength of propagating light and, to a much lesser degree, by the characteristic length of the waveguide's long-range nonuniformity. For this reason, the transmission spectrum of a thin waveguide allows immediate and quite accurate determination of its thickness. An experimental test of these facts is performed for a tapered microfiber. Good agreement with the recently developed theory of adiabatic microfiber tapers is demonstrated.

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text M. Sumetsky, Y. Dulashko, and D. J. DiGiovanni, "Optical surface microscopy with a moving microsphere," in Integrated Photonics Research and Applications/Nanophotonics, Technical Digest (CD) (Optica Publishing Group, 2006), paper NThD3. Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article

This paper describes the theory of a microfiber loop resonator (MLR) and experimentally demonstrates a high quality factor MLR in free space. The MLR is fabricated from the /spl sim/1-/spl mu/m diameter waist of a biconical fiber taper using the CO/sub 2/ laser indirect heating technique. The high coupling efficiency of an MLR is achieved through an adiabatically slow variation of the microfiber diameter in the coupling region. An MLR-loaded Q-factor of 120 000 and an intrinsic Q-factor of 630 000 were demonstrated. As an application, the performance of an MLR as an ultrafast direct contact temperature sensor is also demonstrated. The MLR heating/cooling relaxation time was measured to be /spl sim/3 /spl mu/s, in good agreement with the developed theory.