Abstract: Optical couplers having attachment features are disclosed. A typical coupler according to the present invention couples an optical signal from an optical fiber to a channel waveguide by overlapping the cores of the optical fiber and channel waveguide along a portion of their waveguide lengths, with a spacing distance between the cores of not more than 20 microns for single-mode light coupling, and not more than 100 microns for multi-mode light coupling. This is in contrast to a prior art coupler, which seeks to position the ends of the two cores in a facing relationship. In embodiments according to the present invention, attachment films may be disposed in the overlapping regions to provide advantageous coupling arrangements and new types of opto-electric devices.

Abstract: An assembly comprising first and second electronic devices and an optical resonator that optically couples an optical waveguide on the first electronic device to an optical waveguide on the second electronic device. In this way, optical proximity communication between the devices is possible. The electronic devices may be integrated circuit chips. A first portion of an optical resonator is disposed in a pit of the first device to optically couple the optical resonator to the first optical waveguide. A second portion of the optical resonator is disposed in a pit of the second device to optically couple the optical resonator to the second optical waveguide. Thus, the optical resonator optically couples the first optical waveguide to the second optical waveguide.

Abstract: An optical microresonator system and a sensor system incorporating same are disclosed. The optical microresonator system includes an optical waveguide and an optical microcavity that is optically coupled to the optical waveguide. The microcavity is capable of supporting primarily one or more resonant modes. The optical microresonator system further includes an optical microresonator that is optically coupled to the microcavity and is capable of supporting a resonant mode.

Abstract: Apparatuses and methods for modulating electromagnetic radiation are disclosed. A plasmon waveguide including an array of metallic nanoparticles disposed on a dielectric substrate is provided. The plasmon waveguide is disposed on a MEMS structure. An electromagnetic radiation signal is applied to a tapered fiber disposed proximate the MEMS structure. The intensity of the electromagnetic radiation signal passing through the tapered fiber is modified by displacing a deformable member of the MEMS structure to modify a distance between the plasmon waveguide and the tapered fiber such that an evanescent field of the tapered fiber causes a plasmon resonance in the plasmon waveguide.

Abstract: The present invention is a method and an apparatus for minimizing losses in wavelength selective filters. In one embodiment, an apparatus includes a waveguide bus defined in a first crystalline layer of the apparatus, for receiving incoming light, a resonator defined in the first crystalline layer, and a coupling structure defined in a second polysilicon or amorphous silicon layer of the apparatus, for coupling a selected wavelength of the incoming light from the waveguide bus to the resonator.

Abstract: Our invention relates generally to an optical switch (31) and an optical router (10) to rapidly route signals from particular channels (22, 24) within an optical band by using optical switches (20) which utilize a controlled whispering gallery mode (WGM) resonance of dielectric microspheres (S1, S2, S3) to optically switch signals. Another invention relates to optical filters which use a WGM resonate structure (150) to isolate and switch specific optical signals between waveguides (F1, F2). In other inventions, the filter (100) is switched “on/off” by signal loss within a WGM resonate structure (150) which disrupts the WGM resonance; the filter (100) isolates and switches a specific wavelength signal from among a group of signals of different wavelengths; and is switched “off” by adjusting the index of refraction of the resonate structure to become substantially similar to the index of refraction of the surrounding medium.

Abstract: An optical waveguide structure has a single port on one input/output side, a plurality of ports on another input/output side and an S-curve optical waveguide portion arranged on the outermost side of the waveguide structure and including a first circular arc optical waveguide portion and a second circular arc optical waveguide portion connected thereto. The waveguide portion also has a third circular arc optical waveguide portion extending from a first splitting/coupling point side in the first circular arc waveguide portion toward the plural/ports side and having a curvature inverted relative to the first circular arc optical waveguide portion. At the first splitting/coupling point, a tangential line of the first circular arc optical waveguide portion and a tangential line of the third circular arc optical waveguide portion are parallel to and spaced from each other.

Abstract: SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1-xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Embodiments of the invention having a surface parallel configuration are especially suitable for use in fiber coupled devices. Such surface parallel devices have light propagating in the plane of the quantum wells, in a device geometry that is preferably not single-mode waveguided.

Abstract: A method of filtering optical signals (300) utilizing an optical fiber (100A-100D). The method of filtering optical signals (300) includes the steps (304) selecting an optical fiber (100A-100D) coupled to a source of optical signals, (306) disposing a core (102) in the bore (103) of the optical fiber (100A-100D) formed of a core material (105), (308) selecting a core material (105) to provide a waveguide within the optical fiber (100A-100D), (310) disposing an optical grating (114-1) in a first optical cladding layer (104) disposed about the core (102), (312) propagating an optical signal within the optical fiber (100A-100D) guided substantially within the core (102), (314) modifying a propagation path of selected wavelengths comprising said optical signal with the optical grating (114-1), and (316) determining selected wavelengths for which the propagation path is modified by selectively varying an energetic stimulus to the core (102) thereby tuning the waveguide.

Abstract: Apparatuses and methods for modulating electromagnetic radiation are disclosed. A plasmon waveguide including an array of metallic nanoparticles disposed on a dielectric substrate is provided. The plasmon waveguide is disposed on a MEMS structure. An electromagnetic radiation signal is applied to a tapered fiber disposed proximate the MEMS structure. The intensity of the electromagnetic radiation signal passing through the tapered fiber is modified by displacing a deformable member of the MEMS structure to modify a distance between the plasmon waveguide and the tapered fiber such that an evanescent field of the tapered fiber causes a plasmon resonance in the plasmon waveguide.

Abstract: Microresonators, such as a microsphere resonators and planar microresonators, are optically coupled to waveguides for input and output of light. It is important that the relative positions of the microresonator and the waveguide are maintained stable, while still maintaining high cavity Q and ease of launching and extracting the optical beams. Structures are provided on a substrate that are useful for maintaining the position of the microresonator relative to the waveguide. The structures provide for vertical or horizontal coupling between the waveguide and the microresonator.

Abstract: A composite evanescent waveguide can include a first structured dielectric layer and a second dielectric material oriented adjacent one another to form a wave propagation interface between the first structured dielectric layer and second dielectric material. Each of the first structured dielectric layer and second dielectric material are formed of materials such that the wave propagation interface can be capable of propagating an all-evanescent surface wave. The resulting propagating surface waves tend to have low losses and can be suitable for optical communications, surface analysis, sensors, and a variety of other applications.

Abstract: A four-port optical filter is provided including two tapered optical fibers, each having a loop in the area of their tapered portions, which are located relative to one another to form a ring resonator. The optical filter has a low Q with a broadband filter response which is useful as a channel interleaver or de-interleaver for dense wavelength division multiplexing and other applications.

Abstract: An electro-optical switch implemented in coupled photonic crystal waveguides is disclosed. The switch is proposed and analyzed using both a finite-difference time-domain (“FDTD”) method and a plane wave expansion (“PWM) method. The switch may be implemented in a square lattice of silicon posts in air, as well as in a hexagonal lattice of air holes in a silicon slab. Switching occurs due to a change in the conductance in the coupling region between the photonic crystal waveguides, which modulates the coupling coefficient and eventually causes switching. Conductance may be induced electrically by carrier injection or optically by electron-hole pair generation. The electro-optical switch has low insertion loss and optical crosstalk in both the cross and bar switching states.

Abstract: An optical microresonator includes microcylinder and spiral resonant waveguide formed on the microcylinder that optically couples light from an optical source waveguide to the microcylinder and slows light propagating along the microcylinder. A coupling element, for example, a diffraction grating can be operative with the resonant waveguide structure and configured to meet a desired phase matching A second microcylinder having a spiral resonant waveguide formed thereon can be positioned adjacent to the spiral resonant waveguide formed on the first microcylinder for coupling therewith. The spiral resonant waveguides on first and second microcylinders can be configured for slowing light propagating along the microcylinder.

Abstract: A single-mode optical waveguide with a core, surrounded by a cladding consisting of an inner soft layer and an outer harder layer is described. The outer layer has a grating structure on its inner surface, whose spatial frequency is the same as that of the guided mode. The thickness of the inner cladding is sufficient to keep the grating outside the mode field in undeformed regions of the waveguide, so that normally no out-coupling of the light results. Connections are made by crossing two such waveguides at an angle and pressing them together. This results in deformation of the two waveguides such that the gratings are brought into proximity with the cores. Light is coupled out of one waveguide and into the other in the deformed region, resulting in a self-aligning optical connection. The out-coupled light propagates normal to the waveguide axis, so errors in the crossing angle cause little change in efficiency.

Abstract: A composite evanescent waveguide can include a first structured dielectric layer and a second dielectric material oriented adjacent one another to form a wave propagation interface between the first structured dielectric layer and second dielectric material. Each of the first structured dielectric layer and second dielectric material are formed of materials such that the wave propagation interface can be capable of propagating an all-evanescent surface wave. The resulting propagating surface waves tend to have low losses and can be suitable for optical communications, surface analysis, sensors, and a variety of other applications.

Abstract: An object of the present invention is to provide a multiplexer/demultiplexer capable of preventing a decrease in multiplexing/demultiplexing efficiency due to an error in wavelength or due to a crosstalk with other wavelengths. A two-dimensional photonic crystal having holes 22 cyclically arranged is provided with an input waveguide 23 and an output waveguide 24. Located between the two waveguides are two point-like defects 25 and 26, each consisting of a region devoid of the holes 22. From the light including various wavelengths and propagating through the input waveguide 23, the two point-like defects extract a ray of light having a wavelength determined by the shape of the point-like defects and introduce it into the output waveguide 24.

Abstract: An integrated optical device is disclosed comprising a substrate, optical waveguide, and compound optical resonator having a temperature sensor, at least two coupled optical resonators, and a heater localized to each optical resonator. An optical input signal is coupled to one of the resonators making up the compound resonator to form an optical output signal. The center wavelength and shape of the output signal is optimized with a feedback loop using the temperature sensor to control the power dissipated in at least one of the localized heaters.

Abstract: This application describes optical resonators having deposited optical material layers and optical resonators having layered structures to support whispering gallery modes.

Abstract: Fast, all optical switching of light is provided on silicon, using highly light confining structures to enhance the sensitivity of light to small changes in refractive index. In one embodiment, the light confining structures are silicon micrometer-size planar ring resonators which operate with low pump light pulse energies.

Abstract: Various embodiments of the present invention are related to photonic systems and methods that can be used to encode data in carrier electromagnetic waves. In one embodiment of the present invention, a photonic system comprises a first waveguide configured to transmit a number of electromagnetic waves. The photonic system includes a photonic crystal with a resonant cavity and is configured to selectively and evanescently couple one or more of the electromagnetic waves from the first waveguide into the resonant cavity. The photonic system also includes a second waveguide positioned to transmit and extract one or more electromagnetic waves from the resonant cavity via evanescent coupling.

Abstract: Substrates, systems and methods for analyzing materials that include waveguide arrays disposed upon or within the substrate such that evanescent fields emanating from the waveguides illuminate materials disposed upon or proximal to the surface of the substrate, permitting analysis of such materials. The substrates, systems and methods are used in a variety of analytical operations, including, inter alia, nucleic acid analysis, including hybridization and sequencing analyses, cellular analyses and other molecular analyses.

Abstract: A method of fabricating a passive polarization sorter includes the steps of providing first and second waveguides. The first waveguide has an input and an output. The first waveguide supporting at least one guided TE polarized mode of mode ranking mode-i-TE and at least one guided TM polarized mode of mode ranking mode-j-TM. The second waveguide is positioned adjacent to the first waveguide, and the first and second waveguides are shaped to form an adiabatic region in which light having one of the TE and TM polarized modes remains within the first waveguide, and light having the other one of the TE and TM polarized modes evanescently couples into the second waveguide.

Abstract: A system is provided including a first waveguide having an optical input and a first optical output. A second waveguide includes a second optical output. A coupling region is between the first waveguide and the second waveguide. The coupling region controllably couples the first waveguide and the second waveguide when a field is applied to the coupling region. The strength of the field is variable to control the coupling. Further, the first waveguide, the second waveguide, and the coupling region may be made of electro-optical material. In another example, a component is provided including a substrate and an electro-optical material formed on the substrate. A first and second waveguide are formed of said electro-optical material. An electrode structure is formed proximal to the first waveguide and the second waveguide. The electrode structure selectively provides an electric field in the electro-optical material when a voltage is applied to the electrode structure.

Abstract: A system is provided including a first waveguide having an optical input and a first optical output. A second waveguide includes a second optical output. A coupling region is between the first waveguide and the second waveguide. The coupling region controllably couples the first waveguide and the second waveguide when a field is applied to the coupling region. The strength of the field is variable to control the coupling. Further, the first waveguide, the second waveguide, and the coupling region may be made of electro-optical material. In another example, a component is provided including a substrate and an electro-optical material formed on the substrate. A first and second waveguide are formed of said electro-optical material. An electrode structure is formed proximal to the first waveguide and the second waveguide. The electrode structure selectively provides an electric field in the electro-optical material when a voltage is applied to the electrode structure.

Abstract: Substrates, systems and methods for analyzing materials that include waveguide arrays disposed upon or within the substrate such that evanescent fields emanating from the waveguides illuminate materials disposed upon or proximal to the surface of the substrate, permitting analysis of such materials. The substrates, systems and methods are used in a variety of analytical operations, including, inter alia, nucleic acid analysis, including hybridization and sequencing analyses, cellular analyses and other molecular analyses.

Abstract: An optically coupled resonant pressure sensor includes a deformable diaphragm and an optically coupled resonator fixedly attached to the deformable diaphragm. The resonator includes a resonator body and a laterally offset photodiode adjacent to the resonator body. The resonator is driven by an electric field generated between the laterally offset photodiode and the resonator body when an incident light strikes the photodiode. Pressure applied to one side of the deformable diaphragm causes a shift in a resonant frequency of the resonator. Also disclosed are a method and system for determining pressure.

Abstract: An evanescent-field sensor system and method of using the system to detect either liquid- or airborne biological pathogens, chemical agents, and other harmful or toxic species is provided. The sensor system involves 1) an evanescent-field sensor having a substrate surface with at least a partial bio- or chemo-responsive layer, which forms a part of a serially renewable sensing region; 2) an optical interrogation apparatus for monitoring the bio- or chemo-responsive layer; and 3) an air-fluid delivery system. The optical interrogation apparatus has a light source, an optical delivery system, and a detection instrument or device. The air-fluid delivery system includes either macro or micro-fluidic passages designed to convey biological or chemical analytes to a sensing region.

Abstract: A variety of structures, methods, systems, and configurations can support plasmons for logic.

Abstract: Method and apparatus enable optical evanescent sensing utilizing a waveguide with an annular core. The annular core can provide detectable sensitivity to a measurand due to optical interactions with contents along an inside surface of the annular core since optical properties of the contents vary with changes in the measurand.

Abstract: Devices and techniques for filtering RF or microwave frequencies by optical filtering using a tunable optical filter.

Abstract: An integrated optical mode transformer provides a low loss interconnection between an optical fiber and an integrated optic waveguide having a spot size different from that of the fiber. The mode transformer is comprised of two waveguide layers, an upper layer and a lower layer, with the upper layer being contiguous to the lower layer. The lower layer is the integrated optic waveguide layer forming the optical circuit. The input dimensions of the composite two-waveguide structure supports a fundamental mode that accepts all of the light present on the optical fiber. The upper waveguide layer is tapered down from an input width to an output width and then terminates in such a way that at the termination substantially all of the input optical power resides in the lower waveguide layer. The two-waveguide layer structure is fabricated by deposition and planarization techniques.

Abstract: The invention provides a wavelength selective optical device in which a light emitted from an end surface of a first optical fiber that propagates optical signals with a plurality of multiplexed wavelengths is incident on a first end surface of a first graded index rod lens, then a parallel light beam emitted from a second end surface of the first graded index rod lens is incident on an optical filter arranged to face to the second end surface of the first graded index rod lens, and then a light reflected by the optical filter is incident again on the second end surface of the first graded index rod lens so as to couple to a second optical fiber arranged on a first end surface side of the first graded index rod lens, wherein a refractive index distribution constant of the first graded index rod lens is set such that a center wavelength of the light reflected by the optical filter is positioned within a desired range.

Abstract: An optical fiber comprises core and cladding regions configured to guide the propagation of light (or radiation) in the core region. The cladding region includes a periodic structure configured to produce light guiding by bandgap confinement. In order to suppress higher order odes (HOMs) in the core region, the cladding region includes at least one perturbation region configured so that a mode of the cladding region is resonant with a HOM of the core region. In a preferred embodiment of my invention, the perturbation region is configured so that the fundamental mode of the cladding region is resonant with a HOM of the core region.

Abstract: An integrated optical device is disclosed comprising a substrate, optical waveguide, and compound optical resonator having a temperature sensor, at least two coupled optical resonators, and a heater localized to each optical resonator. An optical input signal is coupled to one of the resonators making up the compound resonator to form an optical output signal. The center wavelength and shape of the output signal is optimized with a feedback loop using the temperature sensor to control the power dissipated in at least one of the localized heaters. The power dissipated in the remaining resonator heaters is set according to a predetermined function having as an input variable the power dissipated in the resonant heater under control of the said feedback loop.

Abstract: A new method to form a VLSI-photonic heterogeneous system device is achieved. The method comprises providing an optical substrate comprising at least one passive optical component formed therein. An electronic substrate is provided comprising at least one active electronic component formed therein. A plurality of metal pillars are formed through the optical substrate and protruding out a first surface of the optical substrate. A plurality of metal pads are formed on a first surface of the electronic substrate. The optical substrate and the electronic substrate are bonding together by a method further comprising aligning the first surfaces of the optical and electronic substrates such that the protruding metal pillars contact the metal pads. The optical and electronic substrates are then thermally treated such that the metal pillars bond to the metal pads.

Abstract: Methods and apparatus are provided for detecting one or more contaminant particles in an environment with an optical sensor. The sensor includes at least one optical waveguide in a resonant arrangement and a light source positioned in an environment in which the presence of a contaminant particle is sought to be determined. The at least one optical waveguide is of a diameter that an evanescent tail of the lightwave extending there through extends into the environment and is reactive to at least one contaminant particle in the surrounding environment. A detector is positioned to receive light indicative of the sharpness of the optical resonance lineshape of the optical resonator at a pre-selected optical wavelength. The detected information determines the specific contaminant particle in the environment and the concentration of the contaminant particle in the environment.

Abstract: An apparatus comprises an optical transmission element, a diffractive element set formed in or on the transmission element, and an optical component. The diffractive element set is positioned to enable spatial overlap of diffractive elements and an evanescent optical signal propagating in a suitably positioned optical waveguide. The diffractive elements are arranged to establish optical coupling between respective optical signals propagating within the transmission element and the optical waveguide. The optical component is arranged to launch or receive the optical signal propagating within the transmission element. The diffractive element set is arranged so that the optical signal in waveguide is successively incident on the diffractive elements. The optical apparatus can further include the optical waveguide, with the optical waveguide and the transmission element comprising discrete, assembled subunits.

Abstract: A multi-port planar evanescent coupler having N inputs and M outputs, where both N and M are each no less than three, formed of combinations of at least one of at least one planar evanescent 2×2 coupler and at least one planar evanescent 3×3 coupler subunits, with phase shifting segments in selected waveguides disposed between the planar evanescent coupler subunits. The multi-port planar evanescent coupler can be used in phase measurement and detection devices, such as interferometers, optical receivers, and laser gyroscopes.

Abstract: The described integrated planar optical structure comprises a principal waveguide having a core and a cladding that define a first light path ad means sensitive to the light radiated into the cladding comprising at least one secondary waveguide having a core and a cladding that define a second light path. The secondary waveguide has an entry situated in the cladding of the principal waveguide at such a distance from the core of the latter as not to interfere with the propagation of the light along the first optical path and a core section that becomes greater in a first part from the entry onwards to collect the light energy radiated into the cladding. Also described are a system for monitoring the light energy emitted by a source and an optical attenuator that comprise the aforesaid optical structure.

Abstract: A planar lightwave circuit coupler including first and second waveguides with curved coupling portions having radii of curvature selected such that the coupler has a splitting ratio that is substantially wavelength and polarization insensitive.

Abstract: The present invention relates to a monolithic optical component (400) comprising a light-absorbing layer and a waveguide structure (2). The invention is more particularly adapted to a monolithic component (400) comprising an evanescent coupling photodiode (6) integrated with the waveguide (2). The monolithic optical component (400) comprises a light-absorbing layer and a waveguide (2) evanescently coupled with the light-absorbing layer, the waveguide (2) having one end coupled to an input face (12) of the component to receive an input wave, the 10 component (400) being characterized in that the input face is convex.

Abstract: The present invention relates to a device, method, array and use of the device for optical coupling. The device comprises first and second optical waveguides (13, 23) extending longitudinally with cores (14, 24) adapted to guide optical radiation (15), first resonator means, laterally surrounding the first waveguide, comprising first and second resonator members (18, 19), and second resonator means, laterally surrounding the second waveguide, comprising third and fourth resonator members (28, 29). The invention is characterized in that first and second deflector means (16, 26) are adapted to couple radiation propagating in the respectiv first and second waveguides with common radiation modes (30), which modes are defined by adjustable geometrical and material properties of the device, so as to obtain wavelength selective coupling of radiation guided by the first and second waveguides, provided the resonator means are tuned to the same resonance wavelength.

Abstract: A tuneable grating assisted directional optical coupler to couple a transmission signal has a first waveguide including a first core and a first cladding, the first waveguide having a first effective refractive index. The coupler also has a second waveguide including a second core and a second cladding, the second waveguide having a second effective refractive index different from the first effective index and being in substantially close proximity to the first waveguide in a predetermined region to provide coupling therebetween. A periodic perturbation is positioned in the coupling region to cause the coupling to be wavelength selective for one given wavelength function of the first and/or the second effective refractive index. Additionally, the second cladding of the second waveguide has a tuneable material and the first cladding of the first waveguide has a non-tuneable material.

Abstract: Optical packages are disclosed. In one aspect, an optical package may include a surface, a microelectronic device coupled with the surface, a first waveguide coupled with the microelectronic device, a second waveguide having a first end that is evanescently coupled with the first waveguide and a second end, a first thickness of a cladding material disposed between the second end and the surface, and a second thickness of a cladding material disposed between the first end and the first waveguide. The first thickness may be greater than the second thickness. Methods of making the optical packages are also disclosed. Apparatus and methods of aligning operations on optical packages are also disclosed.

Abstract: An exemplary embodiment of the present invention described and shown in the specification and drawings is a system including an optical resonator and an optical element having a periodic structure for coupling of light into the optical resonator.

Abstract: An apparatus and method for the detection of oxygen using optical fiber based evanescent light absorption. Methylene blue was immobilized using a sol-gel process on a portion of the exterior surface of an optical fiber for which the cladding has been removed, thereby forming an optical oxygen sensor. When light is directed through the optical fiber, transmitted light intensity varies as a result of changes in the absorption of evanescent light by the methylene blue in response to the oxygen concentration to which the sensor is exposed. The sensor was found to have a linear response to oxygen concentration on a semi-logarithmic scale within the oxygen concentration range between 0.6% and 20.9%, a response time and a recovery time of about 3 s, ant to exhibit good reversibility and repeatability. An increase in temperature from 21° C. to 35° C. does not affect the net absorption of the sensor.

Abstract: Optical couplers having attachment features are disclosed. A typical coupler according to the present invention couples an optical signal from an optical fiber to a channel waveguide by overlapping the cores of the optical fiber and channel waveguide along a portion of their waveguide lengths, with a spacing distance between the cores of not more than 20 microns for single-mode light coupling, and not more than 100 microns for multi-mode light coupling. This is in contrast to a prior art coupler, which seeks to position the ends of the two cores in a facing relationship. In embodiments according to the present invention, attachment films may be disposed in the overlapping regions to provide advantageous coupling arrangements and new types of opto-electric devices.

Abstract: Systems and method for manipulating optical pulses to implement an optical switch and for pulse shaping (e.g., pulse compression and/or compression) are disclosed. In one embodiment, the system comprises an optical switch apparatus that includes a plurality of resonators optically coupled to a waveguide, two output waveguides, an input light source, a control light source. The system selects some of the input signals emitted from the input light course using control signals emitted from the control light source to route to one of the output waveguides. In another embodiment, the system includes a waveguide optically coupled to a plurality of resonators, input light source, optional resonator modules that can change the refractive index of the resonators, and an optional amplifier. This system can change the shape of the pulses by changing a number of parameters, such as the incoming pulse amplitude and/or the refractive index of the resonators.