Abstract: The present disclosure relates to a method of fabricating a reflector, the reflector being at least partially reflective and at least partially transmissive for at least a wavelength of electromagnetic radiation; the method comprising: forming a first material layer defining a bottom layer; forming a sacrificial layer on the bottom layer; forming a second material layer defining a top layer on the sacrificial layer and a supporting structure connected to the bottom layer; and removing at least part of the sacrificial layer to form a cavity between the bottom layer and the top layer such that the supporting structure supports the top layer relative to the bottom layer and no further supporting structure is provided within the cavity, wherein after the at least part of the sacrificial layer is removed, at least the top layer has residual tensile stress.

Abstract: A method of stimulating a MicroElectroMechanical Systems (MEMS) structure (e.g. a cantilever), and an optical sensor for use in such a method, using optical radiation pressure instead of electrostatic pressure, or the like. An optical pulse creates optical radiation pressure which stimulates movement of the MEMS structure and then movement of the MEMS structure may be measures. An interrogating light may be input after the optical pulse to measure movement of the MEMS structure. Advantageously, the same light source can be utilized to stimulate movement of the MEMS structure and to measure movement of the MEMS structure.

Abstract: The present disclosure relates to a method of fabricating a reflector, the reflector being at least partially reflective and at least partially transmissive for at least a wavelength of electromagnetic radiation; the method comprising: forming a first material layer defining a bottom layer; forming a sacrificial layer on the bottom layer; forming a second material layer defining a top layer on the sacrificial layer and a supporting structure connected to the bottom layer; and removing at least part of the sacrificial layer to form a cavity between the bottom layer and the top layer such that the supporting structure supports the top layer relative to the bottom layer and no further supporting structure is provided within the cavity, wherein after the at least part of the sacrificial layer is removed, at least the top layer has residual tensile stress.

Abstract: An optical sensor including a MEMS structure, and a grating coupled resonating structure positioned adjacent to the MEMS structure, the grating coupled resonating structure comprising an interrogating grating coupler configured to direct light towards the MEMS structure. The interrogating grating coupler is two dimensional, and the interrogating grating coupler and the MEMS structure form an optical resonant cavity.

Abstract: A method of stimulating a MicroElectroMechanical Systems (MEMS) structure (e.g. a cantilever), and an optical sensor for use in such a method, using optical radiation pressure instead of electrostatic pressure, or the like. An optical pulse creates optical radiation pressure which stimulates movement of the MEMS structure and then movement of the MEMS structure may be measures. An interrogating light may be input after the optical pulse to measure movement of the MEMS structure. Advantageously, the same light source can be utilised to stimulate movement of the MEMS structure and to measure movement of the MEMS structure.

Abstract: A system for performing atomic force measurements including: a sensor including: a beam having a first side and a second side, the beam including a tip positioned on a surface of the first side for interacting with a sample; and a grating structure positioned adjacent the second side of the beam, the grating structure including an interrogating grating coupler configured to direct light towards the beam; a light source optically coupled to an input of the sensor for inputting light; and an analyser coupled to an output of the sensor; wherein the beam and the interrogating grating coupler form a resonant cavity, a movement of the beam modulates the light source and the analyser determines a deflection of the beam according to the modulated light.

Abstract: An apparatus for detecting a deflection of a beam, the apparatus comprising a beam having a first side and a second side; and a grating structure positioned adjacent the second side of the beam, the grating structure including an interrogating grating coupler configured to direct light towards the beam; wherein the beam and the interrogating grating coupler form a resonant cavity, and light input to the resonant cavity is modulated according to the deflection of the beam.

Abstract: An optical sensor including a MEMS structure, and a grating coupled resonating structure positioned adjacent to the MEMS structure, the grating coupled resonating structure comprising an interrogating grating coupler configured to direct light towards the MEMS structure. The interrogating grating coupler is two dimensional, and the interrogating grating coupler and the MEMS structure form an optical resonant cavity.

Abstract: An apparatus for detecting a deflection of a beam, the apparatus comprising a beam having a first side and a second side; and a grating structure positioned adjacent the second side of the beam, the grating structure including an interrogating grating coupler configured to direct light towards the beam; wherein the beam and the interrogating grating coupler form a resonant cavity, and light input to the resonant cavity is modulated according to the deflection of the beam.

Abstract: An apparatus for detecting a presence of one or more analytes in a sample. The apparatus comprises a cantilever (205) and a grating coupled resonating structure (210). The cantilever (205) comprises an analyte selective coating that is selective to the one or more analytes. The grating coupled resonating structure (210) is positioned adjacent to the cantilever (205). The first grating coupled resonating structure comprises a first interrogating grating coupler (220) which together with the cantilever forms an optical resonant cavity.

Abstract: An apparatus for detecting a presence of one or more analytes in a sample. The apparatus comprises a cantilever (205) and a grating coupled resonating structure (210). The cantilever (205) comprises an analyte selective coating that is selective to the one or more analytes. The grating coupled resonating structure (210) is positioned adjacent to the cantilever (205). The first grating coupled resonating structure comprises a first interrogating grating coupler (220) which together with the cantilever forms an optical resonant cavity.

Abstract: An apparatus for detecting a presence of one or more analytes in a sample. A plurality of optical cantilevered waveguides (200a, 200b) are optically coupled to an optical circuit between an input and an output of the circuit. Each of the optical cantilevered waveguides (200a, 200b) have an analyte selective coating, at least two of the waveguides having different analyte selective coatings. A detection module (304) analyses the output of the circuit to detect the presence of analytes in the sample.

Abstract: An example tunable cavity resonator for filtering radiation in the optical and IR wavelengths and an example method for fabricating same. The example resonator includes a pair of reflectors, one in fixed relationship to a substrate and the other formed upon a suspended moveable membrane disposed a cavity length from the one reflector. The resonator also includes a pair of spaced apart electrodes either constituted by the reflectors or juxtaposed therewith, which are electrostatically operable to move the membrane and other reflector relative to the one reflector.

Abstract: An example tunable cavity resonator for filtering radiation in the optical and IR wavelengths and an example method for fabricating same. The example resonator includes a pair of reflectors, one in fixed relationship to a substrate and the other formed upon a suspended moveable membrane disposed a cavity length from the one reflector. The resonator also includes a pair of spaced apart electrodes either constituted by the reflectors or juxtaposed therewith, which are electrostatically operable to move the membrane and other reflector relative to the one reflector.

Abstract: A detector device for detecting incident radiation at particular wavelengths is disclosed. The device includes a base layer comprising a substrate. A resonant cavity is formed on the base layer between a pair of reflectors. One reflector is formed by a first reflector layer disposed in fixed relationship with respect to the base layer and the other reflector is formed by a second reflector layer disposed on a membrane in substantially parallel relationship to the substrate. A detector is provided within the cavity to absorb incident radiation therein for detection purposes. By placing the absorbing layer of the detector within the resonant cavity, high quantum efficiency can be achieved using very thin absorbing layers, thus significantly reducing the detector volume and hence noise. Various different arrangements of the detector device and different methods of fabricating the same are also disclosed.

Abstract: A detector device (75) for detecting incident radiation at particular wavelengths is disclosed. The device (75) includes a base layer comprising a substrate (77). A resonant cavity is formed on the base layer between a pair of reflectors. One reflector is formed by a first reflector layer (83) disposed in fixed relationship with respect to the base layer and the other reflector is formed by a second reflector layer (91) disposed on a membrane (89) in substantially parallel relationship to the substrate (77). A detector (79) is provided within the cavity to absorb incident radiation therein for detection purposes. By placing the absorbing layer of the detector (79) within the resonant cavity, high quantum efficiency can be achieved using very thin absorbing layers, thus significantly reducing the detector volume and hence noise. Various different arrangements of the detector device (75) and different methods of fabricating the same are also disclosed.

Abstract: A tunable cavity resonator for filtering radiation in the optical and IR wavelengths and a method for fabricating same. The resonator having a pair of reflectors, one in fixed relationship to a substrate and the other formed upon a suspended moveable membrane disposed a cavity length from the one reflector. The resonator also including a pair of spaced apart electrodes either constituted by the reflectors or juxtaposed therewith, which are electrostatically operable to move the membrane and other reflector relative to the one reflector. A first reflector layer is deposited on the substrate to form the one reflector. A sacrificial layer having a high etch selectivity for releasing the membrane in a suspended and spaced relationship from the one reflector is formed on the first reflector layer. The membrane is deposited on the sacrificial layer using a deposition technique characterised by providing the required intrinsic stress in the membrane.

Abstract: An automatically passivated n-p junction is formed from a p-type body containing Group II and Group VI elements, one of which is mercury. A passivation layer is then formed having at least one window provided therein on a surface of the p-type body. The p-type body is then subjected to a reactive ion etching process using the passivation layer as a mask to form the n-p junction. Ohmic contacts are then formed on the n-type and p-type regions. The method may be extended to form an array of n-p junctions on a semiconductor body having a plurality of p-type material layers.

Abstract: The present invention is a method for determining a carrier conductivity-rier mobility spectrum for a semiconductor sample, having the steps of: exposing the semiconductor sample to a range K of discrete magnetic fields k=1,2, . . . K; for each field obtaining a Hall coefficient R.sub.H and a resistivity .rho., and calculating from R.sub.H (B.sub.k) and .sigma.(B.sub.k) experimental conductivity tensor components .sigma..sub.xx.sup.k (exp) and .sigma..sub.xy.sup.k (exp), and slopes of these conductivity tensor components .sigma.'.sub.xx.sup.k (exp) and .sigma.'.sub.xy.sup.k (exp); selecting a trial carrier conductivity-carrier mobility spectrum s.sub.i corresponding to a plurality I of carrier mobilities .mu..sub.i, i=1,2, . . . I; for each B.sub.j, using this trial carrier conductivity-carrier mobility spectrum to calculate conductivity tensor components .sigma..sub.xx.sup.j and .sigma..sub.xy.sup.j, and slopes of the conductivity tensor components .sigma.'.sub.xx.sup.j and .sigma.'.sub.xy.sup.

Abstract: A method and apparatus for producing the conductivity-mobility spectrum of an isotropic semiconductor material, and hence infer the mobility and concentration of carriers in the material. Hall voltage and material conductivity are measured at a plurality of magnetic field strengths, values of the spectrum estimated for each field strength, and the estimates numerically iterated to produce convergent values for the spectrum. In one embodiment, interim selected values of the spectrum are prevented from going negative, which increases the precision of the ultimate convergent values. In another embodiment, the iteration equations employ damping factors to prevent over-correction from one iteration to the next, thus preventing convergent instabilities. The preferred iteration is the Gauss-Seidel recursion.