Search results for "resonator"
showing 10 items of 193 documents
Polymer based tuneable photonic crystals
2007
We report on the fabrication and characterization of photonic crystal slab waveguide resonators which contain a nanostructured second-order nonlinear optical polymer. The combination of a photonic crystal resonator realized in a second-order nonlinear optical polymer allowed the detection of electro-optical modulation of light with a sub-1-V sensitivity. Furthermore we report on the synthesis of novel nonlinear optical polymers with large second-order hyperpolarizability and improved glass transition temperature. The polymer slab waveguide is micro patterned by means of electron-beam lithography and reactive ion etching. The photonic crystal slab-based resonator consisted of a square lattic…
Er:YAG laser giant-pulse generation
2002
Three possibilities of mid-infrared Er:YAG lasers Q-switching were investigated: mechanical and two electro-optical ones. The mechanical method of Q-switching was proved by using of a rotating mirror placed inside the resonator; Pockels or Kerr cells were used for the electro-optical Q-switching. The Pockels cell was constructed on the basis of the Brewster angle cut LiNb03 crystal; the Kerr cell used a ceramic PLZT material. In all the three cases the Er:YAG laser resonator was plan parallel and it consisted of the rear copper mirror and output coupler with 50-70% reflectivity. The Er:YAG crystal was pumped by one xenon flashlamp in a single elliptical silver coated cavity. The generated g…
Broadband Fabry–Pérot Resonator From Zerodur for Laser Stabilisation Below 1KHZ Linewidth With < 100 HZ/S Drift and Reduced Sensitivity to Vibrati…
2015
Abstract Here we demonstrate the results of creating a two-mirror Fabry-Pérot resonator (FPR) that allows achieving the spectral width of a stabilised laser line below 1 kHz. It had low expansion Zerodur spacer and broadband high reflectance mirrors (99.85% in the range of 630 to 1140 nm). FPR was vertically mid-plane mounted for reduced sensitivity to vibrations and included in two shields inside a vacuum chamber to lower temperature fluctuations. Peltier element was used for temperature stabilisation at zero-expansion temperature. Pound-Drever-Hall (PDH) technique was applied. The signal from FPR was compared to ultra-stable signal (of about 1 Hz linewidth) to form a beat note signal. For…
Numerical 2D And 3D Simulations of a Spherical Fabry–Pérot Resonator for Application as a Reference Cavity for Laser Frequency Stabilisation
2015
Abstract We report on the results of a numerical study of deformations of a spherical Fabry-Pérot cavity that can be used for laser frequency stabilisation. It is demonstrated that for a precise simulation of the cavity deformations a 3D model has to be used instead of a simpler 2D model, which employs simulation on the symmetry plane of the cavity. To lower the sensitivity to environmental perturbations, it is suggested to use a material with a low density and a high Young’s modulus. We also show that the mechanical resonance frequencies of the cavity are mainly determined by the size of the cavity.
All-optical and electro-optical active plasmonic telecom components
2011
Active plasmonics is an attractive emerging field in which the ability to control the surface plasmon polariton (SPP) propagation finds many applications such as realization of fully functional integrated photonic circuitry. We demonstrate both numerically and experimentally switching of the SPP transmission based on two different approaches namely the all-optical and electro-optical at telecom wavelengths. The plasmonic component consists of a compact and efficient SPP switch utilizing highly sensitive ring resonator which has high sensitivity to the refractive index changes. Fabrication was done via e-beam lithography utilizing advanced proximity corrections. The compenents were character…
Whispering gallery mode resonators coated with Au nanoparticles
2019
Whispering gallery mode resonators (WGMRs) are very interesting for sensing because a resonance shift could be caused by any perturbation of the surrounding environment. Additionally such a resonator is coated with nanomaterials to tailor and enhance the sensitivity for a specific purpose. WGMR were fabricated using standard telecommunication fiber and a hydrogen flame, characterized using the scan method to obtain the quality factors and then coated with gold nanoparticles (Au NPs) using dip coating method and characterized again for comparison. Au NPs were chosen because their positive impact on microresonator sensitivity has been mentioned before and the surface can later be functionaliz…
Microwave photoassisted dissipation and supercurrent of a phase-biased graphene-superconductor ring
2021
Irradiating normal-superconducting junctions with microwave photons produce spectacular effects, such as Shapiro steps and photoinduced modifications of the dc supercurrent. Moreover, microwave irradiation can also have other, hitherto unexplored consequences, such as a photoassisted dissipation which is phase dependent. Here we present a finite-frequency measurement of both the dissipation and the supercurrent of a phase-biased graphene-superconductor junction in response to microwave photons. We find that, while the supercurrent response is well described by existing theory, the dissipation exhibits unexpected effects which need new theoretical elucidation. Especially with high frequency …
Devices based on semiconductor nanowires
2009
Recently, nanoelectromechanical systems (NEMS) have attracted much attention due to their unique properties and possible applications that differ greatly from those of microelectromechanical systems. NEMS operating frequencies may achieve giga- and terahertz levels and their power consumption and heat capacity is extremely low. Moreover, integration levels may reach 1012 devices per cm−2. In this review, we present techniques for integrating semiconductor materials in NEMS. In particular, we examine fabrication, structure, properties and potential applications of two main classes of NEMS, namely, resonators and switches.
Cell motility probed by noise analysis of thickness shear mode resonators.
2006
The quartz crystal microbalance (QCM) technique is an emerging bioanalytical tool to study the behavior of animal cells in vitro. Due to the high interfacial sensitivity of thickness shear mode (TSM) resonators it is possible to monitor the formation and breakage of cell-matrix interactions and changes in viscoelasticity of the cell bodies, as well as minute cell volume alterations by the time course of their resonance frequency even with millisecond time resolution. We found that mammalian MDCK-II cells grown on TSM resonators impose characteristic fluctuations on the resonance frequency, which are a quantitative indicator for dynamic activities of the cells on the surface and report on th…
Near-Field Enhancement Optimization by Tapering Terahertz Gold Nanoantennas
We will present the simulation, fabrication and characterization of gold tapered nanoantennas, whose structure is optimized for terahertz near-field enhancement.