Search results for "Resonator"
showing 10 items of 193 documents
Necessary and sufficient conditions for frequency entrainment of quasi-sinusoidal injection-synchonised oscillators
1986
A method is presented which permits the first-approximation exact analysis of the dynamical stability of fundamental-mode injectionsynchronized oscillators (FISO's) characterized by a quasi-sinusoidal quasi-static behavior. By combining small parameter and stroboscopic transformation techniques, the phase-lock stability investigation of an nth-order system is reduced to the simple Hurwitz test on an nth degree polynomial easily obtainable from steady state describing quantities. On this basis, equations for critical locking are also derived, which demonstrate the existence of a pair of limit curves (Locus and Boundary) already conjectured and looked for in the past, but only with partial su…
Plasma Effecton Pulse Parameters of Sound Wave
2019
This article presents the experimental results of the effect of gas discharge plasma on an acoustic wave. It is shown that after a certain intensity of the acoustic wave, the presence of plasma leads to a decrease in the Q -factor of the acoustic resonator, a shift in the acoustic resonance in the gas discharge tube at a lower frequency, and after switching off the acoustics, low-frequency gas oscillations with a frequency of 2 Hz are generated in the tube.
Effect of reflections on phase hologram recording in amorphous As-S-Se films
2002
Experimental and theoretical studies of phase hologram recording in amorphous As-S-Se films with slightly wedge-shaped thickness profile are presented. It is shown that Fabry-Perot resonator effect caused by the interference of multiply reflected light beams inside the sample strongly changes the values of diffraction efficiency and its growth rate as well as the exposure time dependences of diffraction efficiency and transmissivity making them site-dependent and sample-dependent. Absorptivity and recording light intensity inside the sample are also significantly changed. The obtained results can be used to explain the holographic and optical experiments also in other materials with Fabry-P…
GYROCOMPU: Toolbox Designed for the Analysis of Gyrotron Resonators
2020
The key point of gyrotron design is the analysis of the radio frequency (RF) behavior in gyrotron resonators. This article proposes a comprehensive, user-friendly and effective gyrotron design toolbox (GYROCOMPU) based on the MATLAB platform. GYROCOMPU associates a relatively complete set of codes for gyrotron analysis and integrates them together into a graphical user interface (GUI). The solving algorithm of the cold cavity equations and self-consistent equations is improved. The solving method improvement in these calculation algorithms renders the analysis more efficient and accurate. Three typical examples of gyrotrons working in the 140-GHz TE03 mode, 42-GHz TE03 mode, and 140-GHz TE1…
Injection-Locked Flashlamp-Pumped Dye Lasers Of Very Narrow Linewidth
1988
Very high spectral quality flashlamp-pumped dye lasers are described, in which spectral narrowing is achieved by injection-locking of pulsed amplifying cavities to the wavelength of low power single-mode cw lasers. With the help of a fast electronic stabilization of the cavity length, we obtain a reliable complete injection. Peak powers up to 12 kW in 300 ns at a bandwith of 6 MHz are achieved over a 150 nm tuning range between 572 and 722 nm. The repetition rate is 10 Hz, limited mainly by the circulating pumps. Applications of these lasers are found in high resolution coherent Raman spectroscopy and nonlinear difference frequency mixing.
Observation of a nonlinear microfiber resonator
2008
Measurements of the intensity transfer function of a silica microfiber resonator are shown to follow a wide variety of hysteresis cycles, depending on the cavity detuning and the scanning frequency of the range of input powers. We attribute these observations to a nonlinear phase shift of thermal origin and provide a simple model that reproduces well our measurements. The response time is found to be around 0.6 ms.
Development of optical WGM resonators for biosensors
2017
Whispering Gallery Mode (WGM) resonators are very sensitive to nanoparticles attaching to the surface. We simulate this process using COMSOL Wave Optics module. Our spherical WGM resonators are produced by melting a tip of an optical fiber and we measure optical Q factors in the 105 range. Molecular oxygen lines of the air in the 760 nm region are used as reference markers when looking for the shifts of the WGM resonance lines. We demonstrate WGM microresonator surface coating with a layer of ZnO nanorods as well as with polystyrene microspheres. Coatings produce increased contact surface. Additional layer of antigens/antibodies will be coated to make high-specificity biosensors.
Potentialities of glass air-clad micro- and nanofibers for nonlinear optics
2010
Micro- and nanofibers constitute an attractive platform for testing nonlinear devices with millimeter size in a simple and flexible fashion, with potential applications in ultra-fast all-optical communications. In this article, we present challenges that must be addressed and targets that can be reached using such a platform. We describe a tunable laser source capable of delivering pulses with a kilowatt peak power and a sub-0.1-nm linewidth that is specially designed for the study of resonant devices such as the nonlinear loop resonator. Experimental and simulation results are presented for silica microfiber based nonlinear devices. The prospect of developing hybrid devices combining highl…
Whispering Gallery Mode Resonator Temperature Compensation and Refractive Index Sensing in Glucose Droplets.
2021
Among the different types of photonic sensor devices, optical whispering gallery mode resonators (WGMRs) have attracted interest due to their high level of sensitivity, small size, and ability to perform real-time temperature measurements. Here we demonstrate the applicability of temperature measurements using WGMR in both air and liquid environments. We also show that WGMR allowed measurements of the refractive index variations in an evaporating glucose–water solution droplet. The thermal tuning of WGMR can be reduced by coating WGMRs with a thin layer of polymethyl methacrylate (PMMA). Dip-coating the silica microsphere multiple times significantly reduced the resonance shift, partially c…
Setup for Characterization of the Non-Linear Electric Susceptibility in the Microwave Range Applied to a Glass Ceramic
2019
A resonator method exciting eigenresonances of three coupled cylindrical dielectric resonators allows characterizing the non-linear response of low loss and high permittivity materials at frequencies of about 1 GHz. To reach the necessary sensitivity for dielectric non-linearities, the setup ensures that the measured intermodulation can be ascribed to the material under test while all other intermodulation sources are excluded. Electric field amplitudes of several V/mm are obtained at an input power of 100 W. The setup was used to characterize the third order non-linear susceptibility of a glass ceramic.