Annual Meeting Optical Society of America

Crossed resonator configurations for photonic switching

Barbara A. Capron, David A. Holm

Published Jan 1, 1988• 0 citations

Abstract

A possible device concept for photonic switching is the crossed resonator in which two Fabry-Perot resonators with perpendicular cavity axes enclose a nonlinear medium. Light entering one of the cavities can modify the light exiting the other cavity by altering the refractive index of the medium. This configuration has been proposed for use as an optical logic gate.1 In this work we also demonstrate its potential as an optical switch and transistor. We model the device following the single Fabry-Perot cavity work for steady-state fields of Miller2 and for pulsed inputs following Bischofberger and Shen.3 We assume the medium has a Kerr nonlinearity with an intensity-independent background absorption. Using parameters for the organic polymer polydiacetylene (PTS) etched into an optical waveguide, we find differential gains of greater than three for steady-state input fields of reasonable powers and that this device in certain regimes behaves like an optical transistor. For the time-dependent case, we model the medium temporal response by the Debye equation using the medium response time for PTS. We present results for input pulses of varying intensity and duration.

DOI: 10.1364/oam.1988.tug6

Related papers

Possibility of positive-pulse switching in systems of nonlinear Fabry-Perot cavities

Kwongchoi Caisy Ho

The conventional way of using a nonlinear Fabry-Perot cavity as an optical memory requires a negative pulse input to reset the state of the cavity. The possibility of using positive pulses to turn a system of nonlinear Fabry-Perot cavities on and off is studied and it was found that positive pulse switching is possible in a system of two coupled nonlinear cavities. First, Korpel and Lohmann's proposal of using polarization switching in a single nonlinear birefringent cavity was studied. After a detailed investigation of their proposal it was found that positive pulse switching in a single nonlinear Fabry-Perot cavity is not possible. One of the reasons is that the eigen-polarization states of the output of a nonlinear Fabry-Perot cavity cannot be switched independently. Although it is not possible to switch a single nonlinear Fabry-Perot cavity with positive pulses we were able to use the coupling of the eigen-polarization states to implement other kinds of optical switches which were demonstrated experimentally. The cross-talk effect in a metallic Fabry-Perot cavity was also studied. Next, a steady state model of a system of two coupled nonlinear Fabry-Perot cavities was developed and it was found that positive pulse switching is possible in such a system. The output can be turned on and off either by pulses sent into different cavities or by pulses of different magnitudes sent into one cavity. Finally, the dynamic behavior of the coupled cavities system was modeled by extending Goldstone and Garmire's model of a single cavity with one input to a system of two coupled cavities with two inputs. We verified by numerical calculations that positive pulse switching is also possible in the dynamic regime.

Dec 5, 19910 citations

Optical bistable behavior involving photonic crystals nonlinear cavity

K. F. Deng, Du Fang Shi

We present an analytical model and numerical experiments to describe optimal bistable switching involving photonic crystals nonlinear cavity. The involving photonic crystals nonlinear cavity is particularly suitable for large-scale all-optical integration. It is interesting to show that the refractive index of the system can be altered by the incident intensity when the incident frequency is tuned to the evanescent mode and the cavity contains a nonlinear Kerr medium. The response of this system to high-intensity incident waves is studied in detail. A cavity host a localized mode at 1.55 um with a Q of 4000 and a mode volume of 0.055 um3, we predict the onset of bistable reflection at incident powers of ~40 mW. The downstream reflections lead to hysteresis loops in the reflectivity that are topologically distinct from conventional Lorentzian-derived loops characteristic of isolated Fabry-Perot cavities. We provide a stability argument that reveals the unstable branches of these unique hysteresis loops, and we illustrate some of the rich bistable behaviors that can be engineered with such downstream sources, this fact may be used to obtain more flexibility in designing nonlinear devices.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEFeb 11, 20050 citations

Semiconductor waveguides for optical switching

S. Laval

Nonlinear semiconductor waveguides are investigated with respect to their use for optical bistability and temporal optical switching with results given for silicon-on-sapphire devices. The performance of the waveguides is assessed with comparisons to nonlinear Fabry-Perot cavities, and the conditions for optical bistability are theoretically shown to be possible by combining a waveguide and a diffraction-grating coupler. Structures experimentally investigated include semiconductor layers epitaxially grown on substrates having low refractive indices. Optical switching is reported on reflected or transmitted beams and on the guided-wave intensity by means of excitation pulses in the nanosecond or picosecond range. The data confirm the usefulness of nonlinear waveguides as alternative devices for temporal optical switching and logic-gate development in part due to their good switching times.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIEFeb 1, 19911 citation

Dynamic Response of a Nonlinear Fabry-Perot Etalon for Various Medium Response Times

Ali Hassan Khidhir

In this work, the switching nonlinear dynamics of a Fabry-Perot etalon are studied. The method used to complete the solution of the differential equations for the nonlinear medium. The Debye relaxation equations solved numerically to predict the behavior of the cavity for modulated input power. The response of the cavity filled with materials of different response time is depicted. For a material with a response time equal to = 50 ns, the cavity switches after about (100 ns). Notice that there is always a finite time delay before the cavity switches. The switch up time is much longer than the cavity build-up time of the corresponding linear cavity which was found to be of the order of a few round-trip times. The slowing down of the cavity response occurs when the incident intensity is approximately equal to the critical switching intensity. This effect is called critical slowing down. As a result, the response of the cavity is much slower than what could be expected from the steady state analysis. The reflected intensity and the change in round-trip phase have similar dynamic response. In this research, the matlap programs are used to study the switching dynamics of a Fabry-Perot etalon.

Baghdad Science JournalMar 1, 20201 citation

Optical Bistability

Guang S. He

When the output parameter of an optical device could be a multivalued function of the input parameter, this device can be working in an optical bistable status. The most typical optical bistable device is a Fabry–Perot cavity containing a nonlinear optical medium, the refractive index of which depends on the light intensity. Upon the action of an intense input optical beam, the transmitted (or reflected) intensity of this device may exhibit a nonlinear response to the incident light intensity variation and, especially under appropriate working conditions, the characteristic output/input curve may manifest a single (or multiple) hysteresis loop(s). Such type of optical bistable device can be used as an optical differential amplifier, optical switch, optical limiter, optical clipper, optical discriminator, or an optical memory element, depending on the chosen nonlinear medium and operation conditions.

Oxford University Press eBooksOct 30, 20141 citation

Optical memories and switching dynamics of counterpropagating light states in microresonators

Leonardo Del Bino, Niall Moroney, Pascal Del’Haye

The Kerr nonlinearity can be a key enabler for many digital photonic circuits as it allows access to bistable states needed for all-optical memories and switches. A common technique is to use the Kerr shift to control the resonance frequency of a resonator and use it as a bistable, optically-tunable filter. However, this approach works only in a narrow power and frequency range or requires the use of an auxiliary laser. An alternative approach is to use the asymmetric bistability between counterpropagating light states resulting from the interplay between self- and cross-phase modulation, which allows light to enter a ring resonator in just one direction. Logical high and low states can be represented and stored as the direction of circulation of light, and controlled by modulating the input power. Here we study the switching speed, operating laser frequency and power range, and contrast ratio of such a device. We reach a bitrate of 2 Mbps in our proof-of-principle device over an optical frequency range of 1 GHz and an operating power range covering more than one order of magnitude. We also calculate that integrated photonic circuits could exhibit bitrates of the order of Gbps, paving the way for the realization of robust and simple all-optical memories, switches, routers and logic gates that can operate at a single laser frequency with no additional electrical power.

arXiv:2002.02954Optics ExpressDec 21, 202035 citations