Optical MEMS (Microspheres and Ring Resonators): Overview of Recent Progress

Characteristics optimization in single and dual coupled silicon-on-insulator ring (disk) photonic biosensors

Analytical Treatment of Parametric Effects in a Ring Resonator

Optical path length, temperature, and wavelength effects simulation on ozone gas absorption cross sections towards green communications

In this paper a novel microwave photonics beamformer device concept, for single side band (SSB) 40 GHz modulated signals, is presented. The proposed device comprises tunable lasers, flat-top arrayed waveguide gratings (AWG), a Mach Zender Modulator (MZM), an all-pass ring resonator and photodetectors. The device can be produced as a photonic integrated circuit. The signals from the lasers (one for each beamformer radiant element) are multiplexed by the first AWG, modulated, and passed through the all-pass ring resonator. The AWG channel spacing and the ring resonator Free Spectral Range (FSR) are both set to be equal to 100 GHz. The signal is demultiplexed by a second AWG and finally photodetected. By tuning each laser within its corresponding AWG passband, the phase difference between the optical carrier and the 40 GHz microwave modulated signal for each beamformer element can be controlled. The difference is determined by the phase response of the all-pass ring resonator. A critical part of the design is the alignment between the resonances of the ring resonator and both AWGs, but this can be alleviated by using a single AWG in fold-back configuration. The power provided to each beamformer element is different due to the intrinsic non-uniform losses of the AWGs and the ring resonators, but this can also be solved either by properly setting the lasers power, or by means of additional optical amplifiers. The presented analysis is independent of the integration technology. In Silicon photonics, the AWGs and ring resonator can be produced, while the (hybrid) integration of lasers, modulator, photodetectors (and eventually amplifiers) is a challenge. The device can be monolithically integrated on semi-insulating InP technology.

ABSTRACTUtilizing the frequency selection characteristic of ring resonators, self-injection-locking linewidth narrowing and frequency stabilization of distributed feedback laser diodes (DFB-LDs) can be achieved under the aid of ring resonators. In this paper, the self-injection-locking effects of a DFB-LD realized by two fiber ring resonators and an optical waveguide ring resonator are compared. The influences of the resonant peak bandwidth and transmission on linewidth narrowing are demonstrated. It is shown that the mode hopping can be significantly suppressed by employing the optical waveguide ring resonator. This is of great significance for practical applications and integration of the self-injection-locked DFB-LDs.

ABSTRACTA optical fiber device is described which can be used for wavelength division multiplexing, switching of opticalsignals and for optical fiber sensors. The device is formed by taking the central output port of 3 x 3 fused taper Bow-Tie optical fiber coupler back to the central input port to form optical fiber ring resonator with two inputs and two outputs. Keywords: Bow-Tie optical fiber, Optical fiber coupler, Optical fiber ring resonator1. INTRODUCTIONAs well known, an four-port optical fiber ring resonator can be made from a 3 x 3 single mode optical fiber coupler, which cross section of coupling range is plane. The devices can be used for wavelength divisionmultiplexing, switching of optical signals and as optical fiber sensor. Because of the fiuctuationof polarizationstate in single mode optical fiber, the signals of output of the fiber ring resonator with 3 x 3 single mode fiber coupler are unstable. In order to overcome this problem, we should use couplermade of polarization-maintainingoptical fiber. In this paper, we present the analysis and experiment of four-port optical fiber ring resonator witha 3 x

Integrated MOEMS based cantilever sensor for early detection of cancer

A new Ka-band voltage controlled oscillator (VCO) using a planar ring resonator (RR) and a GaAs PHEMT microwave monolithic integrated circuit (MMIC) is presented. The resonator operates at harmonic frequencies and is manufactured on a temperature stable calcium magnesium titanate substrate using photolithographic thin-film processes. An innovative fully automated active laser-trimming procedure is used to adjust the frequency of the free-running oscillator as well as the varactor tuning sensitivity. In addition, automated laser-trimming is used to equalize the electrical length between the ring resonator and the MMIC. High unloaded quality factors of more than 350 have been obtained for the harmonic ring resonator. With these high quality factors a single side-band phase noise of better than -110 dBc/Hz is achieved at an offset frequency of 1 MHz. In addition, the frequency tuning range of the laser-trimming procedure is larger than 10% without any significant change of the VCO's characteristics such as phase noise and varactor tuning sensitivity. The typical temperature drift of the oscillator frequency is less than 4 ppm/K. We use a RR-VCO with an electrical length of four wavelengths, which is phase-locked to an external reference, as a local oscillator in our latest microwave Point-to-Multipoint (PMP) transceivers.

Ring resonators have been widely used for various applications. In this paper, double half ring resonators working at 2.5GHz are proposed for bandpass filter applications. These resonators suppress multiple harmonics (2/sup nd/ and 3/sup rd/ harmonics) and provide size compactness with employing various physical configurations. Conventional circular ring resonators are modified to be transformed to new forms holding double half ring configurations. A closed loop split ring resonator and open loop double half ring resonators are compared to decrease the resonant frequency. Continuously, the open double half ring resonator adds open microstrip lines to additionally reduce the resonant frequency. Open loop structure provides flexible design and lower resonant frequency, in other words, reduction of real estate. 4 different simulated resonators are fabricated and measured. They show very high quality factor and suppression of multiple harmonics.

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation Dimitra A. Ketzaki, Odysseas Tsilipakos, Traianos V. Yioultsis, Emmanouil E. Kriezis; Electromagnetically induced transparency with hybrid silicon-plasmonic traveling-wave resonators. Journal of Applied Physics 21 September 2013; 114 (11): 113107. https://doi.org/10.1063/1.4821796 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAIP Publishing PortfolioJournal of Applied Physics Search Advanced Search |Citation Search

An optomechatronic system based on one-dimensional ultrasound detector array for intravascular pressure measurement is presented. The proposed structure is based on optical linear ring resonators array. The applied pressure on ring resonator will change the physical parameters such as effective cross section of the ring and finally the effective index of refraction. The transmitted intensity changes and the measured output power could be used for measuring the pressure. Also, for rejection of common errors after photodetectors blocks, differential amplifiers can be utilized. For incident light coupling to the rings, the integrated 3-dB couplers are used. The effect of pressure on single ring is simulated and the effects of coupling coefficient, coupler loss and ring resonator diameter are investigated. This structure easily can be extended to two-dimensional cases. So, the proposed structure can be used for intravascular imaging including low noise and high integration and precision.

We deduce equations to calculate coupling coefficients of diamond micro-ring resonators. The equations can be used universally at any wavelength but not limited to the transmission peaks/valleys, and can be adapted with triangular cross-sections and tapered waveguides. Consequently, we build three models in accordance to different diamond processing technologies. These models deal with ring resonators with either rectangular cross sections, or triangular cross sections, or with tapered bus for triangular cross sections. The calculated coupling coefficients can be well fitted by exponential decay functions of gap d. Due to geometrical limitations, triangular-cross-sectional diamond resonators are shown to have much smaller (factor 20) coupling coefficients than those of rectangular-cross-sectional resonators. A tapered bus is shown to be beneficial to increase the coupling coefficient. Besides the calculation of coupling coefficients, the method presented in the paper can also be used to calculate the bending loss of micro-ring resonators, as a complement to the existing methods.

In addition to conventional optical methods for surface studies, various differential phase optical techniques have been developed recently which are capable of detecting variations in optical path length with very high sensitivity (up to 10 angstroms according to theoretical estimations). The differential approach is based on the measurements of phase difference between two beams reflected from two adjacent points of a sample. It results in high depth resolution, but the system response is fairly simple only for step-like structures. The authors propose a novel technique for recovering the surface optical phase relief by numerical treatment of experimentally measured differential phase scan. The image formation theory of the differential phase optical microscope (DPOM) described by Chung is developed and the differential phase scan is -- under certain assumptions -- the finite derivative of the convolution between the phase relief and the amplitude profile of the optical beam on the surface. The experimental data treatment includes the appropriate numerical method for solving the ill- conditioned integral equation to obtain the surface phase relief. This technique has been applied to studies of the refractive index profile of ion-exchanged channel glass waveguides and the surface profile of Ti:LiNbO<SUB>3</SUB> channel waveguides.

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The formula to calculate a variation of optical path length of single crystal by the electric field was derived by this study. The formula was applied to single crystal. The results are as follows. In case of the applied electric field in the body diagonal direction and the passing light along the same direction, the variation of optical path length had the largest value. The symmetry of the space distribution of optical path length satisfied , the set of elements of the symmetry of single crystal. The property which gave the largest influence to the variation of optical path length is the strain of length by the Inverse piezoelectric effect. The second influence, is the variation of the refractive index by the electro-optic effect. The variation of optical path length by the inverse piezoelectric effect and by the electro-optic effect have a reverse sign each other.