Abstract
An integrated thermal sensor comprising photonic crystal elements that enable photonic elements for photonic sourcing, spectral switching and filtering, sensing of an exposed analyte and detection. In embodiments, applications are disclosed wherein these photonic elements provide a spectrophotometer, a photonic channel switch and a standalone sensor for toxic gases and vapors. An application coupled with a mobile phone is disclosed.
Claims
1. An integrated photonic crystal sensor (IPCS) comprising photonic elements, including: a photonic source (PS), a photonic crystal waveguide sensor (PCWS) comprising a photonic crystal (PC), and a photonic crystal waveguide detector (PCWD); and a photonic carrier signal created in the PS that propagates from the PS into and through the PCWS, and terminates in the PCWD, wherein the PCWD receives the photonic carrier signal that propagates through the PCWS and detects an amplitude of the photonic carrier signal, wherein the PCWD is sensitive to the amplitude and wherein the photonic carrier signal is propagated between the photonic elements through separate photonic waveguide (PW) or photonic crystal waveguide (PCW) interposer structures, wherein the PCWS is sensitive to an analyte by way of a detected change in amplitude of the photonic carrier signal wherein the photonic carrier signal is propagated between the photonic elements through separate photonic waveguide (PW) or photonic crystal waveguide (PCW) interposer structures, and further including one or more micro-platforms supported by nanowires in which the one or more micro-platforms is at least partially supported from a surrounding substrate by multiple electrically-conducting phononic nanowires, the one or more micro-platforms comprising one or more of the PS, PCWS, and PCWD wherein said phononic nanowires comprise a layer of crystalline semiconductor further comprising a phononic structure, wherein the phononic structure comprises phonon scattering sites and/or phononic crystal, wherein the layer reduces thermal conductivity and wherein the PS, PCWS, and PCWD are configured to identify a molecular species of the analyte.
2. The IPCS of claim 1 wherein the carrier signal propagates between photonic elements via a photonic waveguide (PW) interposer or photonic crystal waveguide (PCW) interposer.
3. The IPCS of claim 1 wherein one or more photonic elements comprise a resistively heated micro-platform powered from an external source, thereby providing control for a photonic signal amplitude, photonic signal wavelength passband, and platform surface outgassing.
4. The IPCS of claim 1 wherein one or more of the micro-platforms is disposed in an environment reducing convective and conductive thermal heat transport to or from the one or more micro-platforms is reduced for the purpose of self-cooling through spontaneous blackbody radiation.
5. The IPCS of claim 1 wherein one or more of the micro-platforms is cooled by an integral Peltier thermoelectric device.
6. The IPCS of claim 1 wherein the PS comprises a light emitting platform (LEP) and is adapted with a resonant filter split ring resonator (SRR), photonic Bragg grating or LC resonant circuit to provide an infrared photonic carrier signal of reduced bandwidth.
7. The IPCS of claim 1 wherein the first layer of the phononic nanowires comprises a random or periodic deposition of phonon scattering sites within or on the surface of said phononic nanowires, and further wherein the phonon scattering sites are physically separated by distances less than a mean-free-path of heat conducting phonons, thereby reducing thermal conductivity.
8. The IPCS of claim 1 wherein a layer of the phononic nanowires comprises phononic crystal characterized by a phononic bandgap, thereby reducing thermal conductivity.
9. The IPCS of claim 1 wherein a layer of the phononic nanowires comprise one or more of multiple holes, cavities, phononic Bragg line structure, atomic-level superlattices, atomic-level vacancies and implanted particulates disposed physically in random or periodic fashion.
10. The IPCS of claim 1 wherein one or more of the phononic nanowires is comprised of one or more additional layers comprising a metallic atomic layer deposition (ALD) layer for increasing electrical conductivity or mechanical stress control.
11. The IPCS of claim 1 wherein the photonic carrier signal from the PS comprises at least one infrared wavelength band and within an infrared spectral wavelength range.
12. The IPCS of claim 1 wherein the PS comprises one or more of a light emitting platform (LEP), light emitting diode (LED), OLED or laser.
13. The IPCS of claim 1 wherein the PS comprises a heated micro-platform, the micro-platform further comprising a heated blackbody source of radiation structured with one or more of a split ring resonator (SRR), surface plasmon particles, 1-D Bragg grating and LC resonant structure to create a photonic carrier signal of limited bandwidth.
14. The ICPS of claim 1 further adapted with a photonic crystal waveguide filter (PCWF) comprising an additional photonic element disposed into the photonic carrier signal interposer path between the PS and the PCWS, wherein the PCWF modulates the amplitude of the photonic carrier signal.
15. The IPCS of claim 1 wherein an electromagnetic field created by the photonic crystal (PC) structure within the PCWS penetrates into and electromagnetically couples with the molecular structure of the exposed analyte, wherein the coupling modulates the amplitude of the photonic carrier signal.
16. The IPCS of claim 15 wherein the PC of the PCWS is structured with photonic defect sites thereby increasing said coupling.
17. The IPCS of claim 15 wherein the PC structure of the PCWS is configured for slow-wave propagation of the photonic carrier signal thereby increasing said coupling.
18. The IPCS of claim 15 wherein the PC of the PCWS is configured as a Mach-Zehnder interferometer.
19. The IPCS of claim 15 wherein the PCWS is configured with photonic structure sensitive to one or more of a molecular species contained within the exposed analyte, including toxic gas species, volatile hydrocarbons, and complex molecules.
20. The IPCS of claim 1 wherein the PCWD comprises a micro-platform thermally isolated by phononic nanowires and structured with a device for sensing temperature of the micro-platform, wherein the micro-platform is heated by absorption of the photonic carrier signal.
21. The IPCS of claim 20 wherein the temperature sensing device comprises one or more of a Seebeck thermoelectric, pyroelectric, thermistor and MOST device.
22. The IPCS of claim 1 wherein the PCWD comprises a pn junction bandgap diode sensitive to wavelengths over a range from 0.3 micrometers into the infrared range.
23. The IPCS of claim 1 wherein the PS is a narrowband, noncoherent light emitting platform (LEP) supplying a photonic carrier signal comprised of one or more wavelength bands of infrared with the IPCS further configured for operation as an infrared spectrophotometer.
24. The IPCS of claim 1 wherein the PS, PCWS, and PCWD are disposed on a common semiconductor or ceramic substrate.
Description
BRIEF DESCRIPTION OF THE FIGS
(1) FIG. 1A depicts a plan view of a prior art photonic diffraction grating configured as a coupler into a photonic crystal waveguide (PCW) providing one type of a photonic source (PS) when supplied by an emitter external to the chip
(2) FIG. 1B depicts a plan view of a prior art photonic diffraction grating configured as a coupler into a photonic slab waveguide providing a photonic source (PS) when supplied by an emitter external to the chip.
(3) FIG. 2A depicts a plan view of a prior art photonic crystal waveguide (PCW) with a holey waveguide core providing a bandwidth filter or photonic interconnect.
(4) FIG. 2B depicts a plan view of a prior art photonic crystal waveguide (PCW) with a slab waveguide core providing a bandwidth filter or photonic interconnect.
(5) FIG. 3 depicts a plan view of a prior art photonic crystal waveguide (PCW) with a holey core interfaced to a slab waveguides at input and output.
(6) FIG. 4A depicts a plan view of a prior art photonic crystal waveguide sensor (PCWS) structured with two resonant high-Q sensor cavities within the slab core.
(7) FIG. 4B depicts plan view of a prior art photonic crystal waveguide sensor (PVWS) structured with a resonant high-Q sensor cavity embedded into the cladding adjacent to the slab core.
(8) FIG. 4C depicts plan view of a prior art photonic crystal waveguide sensor (PCWS) structured with a Mach-Zehnder interferometer having an internal high-Q resonant sensor cavity.
(9) FIG. 5 depicts a plan view of a prior art photonic crystal waveguide (PCW) with a nonreflecting photonic crystal termination for the photonic carrier signal.
(10) FIG. 6 depicts a plan view of a prior art photonic chip structured with a photonic crystal waveguide sensor and with photonic input and output couplers.
(11) FIG. 7 depicts plan view of a prior art nanowire with phononic scattering structures.
(12) FIG. 8 depicts a plan view of a prior art thermally-isolated micro-platform supported by nanowires with phononic scattering structures.
(13) FIG. 9A depicts a plan view of a photonic crystal waveguide filter (PCWF) element comprised of integrated IP & P structures having temperature control.
(14) FIG. 9B depicts plan view of a second photonic crystal filter (PCWF) embodiment without external temperature control in accordance with embodiments of the invention.
(15) FIGS. 10A, 10B and 10C depict respective first, second and third plan views of photonic crystal waveguide sensor (PCWS) embodiments in accordance with embodiments of the invention.
(16) FIG. 11 depicts a plan view of a photonic crystal waveguide detector (PCWD) comprised of a thermally-isolated and thermally-heated micro-platform further comprising a thermoelectric Peltier array and a photonic crystal waveguide (PCW) terminated in a zero-reflecting termination structure and where one PCW supporting nanowire is comprised of integrated photonic and phononic (IP & P) structures in accordance with embodiments of the invention.
(17) FIG. 12A is a schematic depicting a chip comprising a photonic source (PS), a photonic crystal waveguide sensor (PCWS) and a photonic crystal detector PCWD in accordance with embodiments of the invention.
(18) FIG. 12B is a plan view depicting the chip of FIG. 12A comprising a 1D grating photonic source, a sensor micro-platform with a high-Q resonant cavity embedded in the cladding photonic crystal, and a photonic crystal waveguide detector (PCWD) with integrated photonic and phononic (IP & P) structures in accordance with embodiments of the invention.
(19) FIG. 13A is a schematic depicting a chip comprising a grating portion of a photonic source (PS), a photonic crystal waveguide filter (PCWF), a photonic crystal waveguide sensor (PCWS) and a photonic crystal detector (PCWD) further comprising three IP & P interposer structures in accordance with embodiments of this invention.
(20) FIG. 13B is a plan view depicting structure of the chip of FIG. 13A.
(21) FIG. 14A is a schematic depicting a chip comprised of a photonic source (PS) and with a single micro-platform comprising the sensor (PCWS) and detector (PCWD) in accordance with embodiments of the invention.
(22) FIG. 14B is a schematic depicting a chip comprised of a photonic source PS, a photonic crystal waveguide filter (PCWF) and a single micro-platform comprising both the sensor (PCWS) and detector (PCWD) in accordance with embodiments of the invention.
(23) FIG. 15 is a plan view depicting an integrated thermal sensor chip structured as an embodiment of FIG. 14A wherein the PCWS comprises a Mach-Zehnder interferometer in accordance with the embodiments of the invention.
(24) FIG. 16 is a schematic depicting an integrated thermal sensor chip comprising three photonic sources (PS), five photonic crystal waveguide sensor (PCWS) elements and five photonic crystal waveguide detector (PCWD) elements in accordance with embodiments of the invention.
(25) FIG. 17 is a schematic depicting an integrated thermal sensor chips comprising a photonic source PS, dual photonic crystal waveguide filters (PCWF), a photonic crystal waveguide sensor (PCWS) and a photonic crystal waveguide detector (PCWD) in accordance with embodiments of the invention.
(26) FIG. 18 depicts an integrated thermal sensor disposed on the backside of a mobile telephone in accordance with embodiments of the invention.
(27) FIG. 19A depicts a plan view of a metamaterial-type photonic source (PS) comprised of a light emitting platform (LEP) providing the photonic carrier signal source in accordance with embodiments of the invention.
(28) FIG. 19B depicts a cross-sectional view of the metamaterial-type photonic source (PS) of FIG. 19A.
DETAILED DESCRIPTION
(29) Definitions: The following terms are explicitly defined for use in this disclosure and the appended claims:
(30) “photonic” means electromagnetic energy having wavelengths ranging from visible to millimeters.
(31) “analyte” means a gas, vapor, particulates affecting the photonic carrier signal detected from a photonic crystal waveguide sensor (PCWS) for the purpose of identification, monitoring or calibration.
(32) “photonic element” or “photonic structure” means a structure providing variously a source, interface, coupling, focusing, guiding, switching, termination and sensing for a photonic carrier signal.
(33) “phononic structure” means a structure for sourcing, interfacing, coupling, scattering, and resonating thermal phonons.
(34) “light emitting platform” or “LEP” means a photonic element comprising a thermal micro-platform heated to a temperature providing a photonic source (PS).
(35) “thermoelectric device” means a device for converting a temperature differential into an electrical signal or visa versa.
(36) “photonic waveguide” or “PW” means a conventional photonic waveguide for guiding the photonic signal through a core pathway at least partially surrounded by cladding of a lower effective index of refraction.
(37) “photonic crystal waveguide” or “PCW” means a metamaterial photonic element guiding a photonic wave through a core pathway at least partially surrounded by a cladding structure comprising a photonic crystal.
(38) “photonic crystal waveguide sensor” or “PCWS” means a photonic element comprised of a photonic crystal waveguide (PCW) structure wherein the structure is sensitive to changes in effective refractive index when photonically-coupled to an analyte.
(39) “photonic crystal waveguide filter” or “PCWF” means a photonic element comprised of a photonic crystal waveguide (PCW) structured to modulate the amplitude, phase or channel bandwidth of the photonic carrier signal.
(40) “photonic crystal waveguide detector or PCWD” means a photonic element comprised of a photonic crystal waveguide (PCW) with thermally-dispersive structure and a temperature sensing device.
(41) “photonic zero-reflection termination” means the thermally-dispersive structure within a photonic crystal waveguide detector (PCWD) element providing a termination for the photonic carrier signal.
(42) “spectrophotometer” means an instrument comprised of at least a PS, PCWS and PCWD wherein the magnitude or phase of a photonic carrier level is measured for the purpose of identifying or monitoring an analyte.
(43) “SOI” means a wafer comprised of a semiconductor topside device layer, an intermediate oxide film, and an underlying handle substrate. In the case of silicon SOI, the three sandwich layers are a silicon device layer, silicon dioxide and silicon substrate.
(44) FIG. 9A depicts a photonic element PCWF 900A comprising a thermally isolated micro-platform 920 supported with nanowires 930, 935, 940 and 960 wherein electrical contacts are depicted with bonding pads 980. A photonic carrier signal entering surface 990 propagates through a coupling PCW into a first nanowire 960 comprising a PCW within the PCWF. The photonic carrier signal continues through the PCWF and PCWF nanowire 940 into a second PCW. This photonic carrier signal continues through a second PCW and out through surface 950 into the next photonic element within the cascade of elements.
(45) In the embodiment of FIG. 9A, the temperature of the micro-platform is controlled at the platform level with resistive heater thermal element 970 disposed on thermal micro-platform 920. The thermal device depicted by nanowires 930, 935 comprises one or more of a Seebeck thermoelectric sensor, pyroelectric sensor, thermistor sensor, or Peltier cooler.
(46) In applications, the PCWF modulates the signal carrier level, phase or wavelength passband by temperature control of the micro-platform 920. In embodiments, the PCWF filter provides a signal of reduced bandwidth and in embodiments the PCWF selects a photonic wavelength channel. In some applications, this pixel provides a modulator or switch for photonic signals in the 1150 nm wavelength range.
(47) FIG. 9B depicts a PCWF without a dedicated temperature sensing device. In this embodiment, the input photonic carrier signal from PCW 910 into PCW 960 continues into the PCWF 920. The is modulated by the photonic passband of the PCW within the PCWF micro-platform 920. In this depiction, nanowires 930, 936 provide support for the micro-platform 920 suspended over cavity 921. Structures 960 and 940 are IP & P structures providing input and exit photonic links in addition to thermal isolation of the micro-platform. The micro-platform is powered by an electric power supply connected into contact pads 936 and 980. In one application, a plurality of the PCWF provides a multiplexing switch for photonic signals. The PCW within a filter PWCF in embodiments may be structured to provide slow-wave operation providing a phase delay for the photonic signal. In some embodiments, the PCWF is not configured as a thermal micro-platform and is operated at ambient temperature.
(48) FIGS. 10A, 10B and 10C depict example embodiments of photonic crystal waveguide sensor PCWS elements. A photonic carrier signal enters the PCWS through PCW 910 into port 990, proceeds through nanowire 960, on into the PCW sensing area of micro-platform 920 having a high-Q sensor structure 1061 within the PCW cladding, continues on through a second nanowire 940 and exits into the PCW at exit port 950. The nanowires 960 and 940 comprise PCW structures comprise IP & P structure providing a photonic guide and phononic isolation for the thermal micro-platform 920. The micro-platform 920 and nanowires 960, 940 are disposed over cavity 921. The thermal micro-platform 920 in this embodiment is heated through a resistive heater comprising the active layer of the micro-platform and nanowires 930, 931 with off-platform bonding pad connections 980, 981.
(49) An external electrical power source connected into bonding pads 980, 982 provides current for heating the micro-platform 920. The resistor formed of the series connection of nanowires 930, 931 and the micro-platform 920 in addition provides a thermistor for monitoring the platform temperature.
(50) In the embodiments of FIGS. 10A, 10B and 10C, a PCWS comprising thermal micro-platform 920, nanowires 930, 931, 940, 960 is connected to interposer PCWs at an entrance port 910 and an exit port at 950. The PCWS is structured with PCW wherein the photonic carrier signal propagates as a slow-wave mode. The slow-wave mode can provide a maximum sensitivity with exposure to an analyte of interest. The periodic holes in the cladding structure of the PCW structure creates a negative index dispersion at the spectral bands of interest to reduce the group velocity for the photonic carrier signal propagating through a core of the PCW. In the illustrated PCWS embodiments of the FIGS. 10A, 10B and 10C, the group velocity of the propagating wave through the core is significantly reduced with respect to free space propagation. In embodiments of this invention, the guided wave core may be of slab, holey or slot-type.
(51) The sensor PCWS 1000A depicted in FIG. 10A comprises a single high-Q resonator 1061 imbedded in the cladding area within the PCW of sensor micro-platform 920. Resonator 1061 is electromagnetically coupled to the evanescent tail of the slow-wave propagating through the PCW of the micro-platform 920. Quality factors of 10,000 and higher are achievable with these resonant structures. The resonator provides a high sensitivity to nearby minute changes in refractive index when exposed to an analyte of interest.
(52) The PCWS 1000B of FIG. 10B comprises a single high-Q resonator 1062 disposed in the PCW core and electromagnetically coupled to the slow-wave propagating through the core. In this illustrative embodiment, the core guide is of holey type wherein the resonator 1062 can be considered as a “defect” within the PCW core. In this embodiment the optical carrier signal propagates from the PCW 910 entrance port through to PCW exit port 950 similar to the PCWS of FIG. 10A. The “defect” 1062 in the PCW core is sensitive to an exposed analyte as in FIG. 10A. Provision is made for heating of the sensor micro-platform using an electrical power source connected at pads 980, 981.
(53) Another PCWS 1000C embodiment is depicted in FIG. 10C wherein the PCWS comprises nanowires 930, 931, 960, 1040 supporting thermal micro-platform having an area 1063 sensitive to an exposed analyte. This localized incremental shift in the physical separation and diameter of holes 1063 within the PCW creates a dispersion in the PCW impedance which is sensitive to an exposed analyte. In regions of the PCW 960, 1040 a varying separation between core holes provides a desirable impedance match transition to the PC 910 disposed external to the PCWS.
(54) In the embodiments of FIGS. 10A, 10B and 10C, the thermal heater within the PCWS is used to outgas an analyte remaining on or in the PCWS following a spectrographic measurement. In an exemplary embodiment with a silicon-based thermal micro-platform, the platform is heated to temperatures as high as above 500 degrees C. for the outgassing procedure.
(55) In other embodiments, additional mechanical structures are provided to transport and increase exposure of an analyte to the PCWS. For example, a vaporizer disposed proximal can be used to direct a vapor form of the analyte onto the PCWS. In other embodiments, a robotic cantilever moves microscale analyte samples into close proximity to the PCWS for analysis.
(56) FIG. 11 depicts a photonic crystal waveguide detector PCWD element wherein the photonic carrier signal moving through input port 1090 propagates through nanowire 960 into thermal micro-platform 920 where it thermally dissipates into photonic termination structure 1163. The underlying cavity 921 is bounded by periphery 925 contained within the off-platform support structure. Seebeck thermoelectric devices 1160 and 1161, depicted with four electrically-conducting nanowires, sense the incremental heating of micro-platform 920 as the photonic carrier signal heats PCW structure 1163. The incremental increase of temperature of the micro-platform 920 is proportional to the optical power of the photonic carrier signal delivered into the termination 1163.
(57) In other embodiments of the PCWD, the dissipative termination structure 1163 of FIG. 11 is replaced with dissipative structures comprising, without limitation, resonant RLC loops, low-Q photonic crystal resonators, and a field of nanotubes. In other embodiments, the temperature sensing devices in the PCWD may comprise pyroelectric, thermistor, VOx and MOST devices. In some embodiments, thermoelectric devices depicted as structure 1162, 1164 are operated as Peltier thermoelectric coolers for reducing the steady-state temperature of platform 920. This cooling reduces noise of thermal origin in the sensing devices disposed on platform 925. In other embodiments, structures 1162 and 1164 comprise resistive heaters for outgassing the micro-platform 920 providing an advantageous cleaning function for the PCW termination 1163.
(58) FIG. 12A depicts a spectrophotometer 1200A comprising three photonic elements 100A, 1000A and 1100 and two micro-platforms. Photonic elements PCWS and PCWD comprise separate thermal micro-platforms. In FIG. 12B, PS 100A depicts a photonic Bragg grating receiving photonic carrier signal from the remainder of the PS which is disposed off-chip. In applications, this embodiment provides a spectrophotometer sensitive to an analyte exposed to the sensor PCWS 1000A. The off-chip portion of the PS in embodiments is comprised of an LEP, LED, OLED, or laser including a quantum cascade laser.
(59) FIG. 13A depicts another spectrophotometer comprising four photonic elements. A source PS 100A originates a photonic carrier signal which propagates through PCWF 900A, continues through PWCS 1000A and terminates into PCWD 1100. In applications, this embodiment provides a spectrophotometer sensitive to an analyte exposed to the sensor PCWS 1000A.
(60) FIG. 13B depicts a plan view 1300B of the spectrophotometer 1300A of FIG. 13A. Three PCW coupling structures link the four photonic elements of the spectrophotometer. In this embodiment, the PCWF, PCWS and PCWD correspond to and comprise an IP & P integration of photonic elements disclosed in FIGS. 9A, 10B, and 11, respectively. In exemplary embodiments, the spectrometer of FIGS. 13A and 13B can comprise a single silicon substrate
(61) FIG. 14A depicts a spectrophotometer comprising three photonic elements, a first chip comprising a Bragg grating 100A receiving a photonic carrier signal and a second element comprised of a single thermal micro-platform 1450. The single platform comprises a PCWS and PCWD. The PCWS and PCWD are combined as a single IP & P structure as depicted in the plan view of FIG. 12B.
(62) FIG. 14B depicts a spectrophotometer comprises four photonic elements, the first photonic element comprises a Bragg grating 100A, a second photonic element comprises a PCWF 900A and the third and fourth photonic elements 1450 PCWS, PCWD comprise a single thermal micro-platform. Source element PS 100A provides a photonic carrier signal through a PW and PCW guide into PCWF 900A. Photonic elements PCWF 900A and PCWS, PCWD 1450 are photonically connected through a PCW. The PCWF 900A comprises embodiments as depicted by the PCWF of FIG. 9B. The combined PCWS-PCWF 1450 comprise an IP & P structure further comprised of a single thermal micro-platform.
(63) FIG. 15 is a plan view depicting another embodiment spectrophotometer 1500 wherein a single substrate comprises a Bragg grating 100A of the PS and an IP & P structure further comprising photonic elements PCWS and PCWD. Photonic elements PCWS and PCWD comprise separate micro-platforms within the same suspended structure 920. The PCWS and PCWD are photonically linked through the interposer PCW nanowire 1570 supported separately from the PCWS and PCWD. The shared interposer nanowire PCW 1570 extends fully across IP & P structure 920, wherein the IP & P structure is supported by nanowire 1560 and nanowires within thermal devices 1631, 1632 and 1580.
(64) In operation, the photonic carrier signal from Bragg grating 100A propagates into photonic waveguide PW 1502 and continues into structure 1530 comprising a PCW nanowire 1560 and a Mach-Zehnder interferometer of the PCWS photonic element. The photonic carrier signal continues through the IP & P interposer nanowire 1570 into the PCWD which comprises a dissipative photonic termination 1561. This spectrophotometer is sensitive to an analyte exposed to the Mach-Zehnder interferometer.
(65) The thermal elements 1631, 1632, 1580 within the spectrophotometer of FIG. 15 in embodiments comprise variously a temperature sensor, a resistive heater and a Peltier cooler. In a preferred embodiment, the temperature sensor comprises a thermoelectric Seebeck device.
(66) The schematic of FIG. 16 depicts a more highly integrated IP & P system-on-chip SoC embodiment comprising multiple photonic elements on chip 1600 to provide a more complex spectrophotometer 1600. In this embodiment, each PCWD comprises a separate thermal micro-platform. The other thermal elements ado not comprise a thermal micro-platform. All thermal elements are connected with PCWs. In this embodiment, each of three photonic sources PS 100A, 100B, 100C provide a photonic carrier signal which propagates through a photonic guide PW or PCW into five PCWS elements 900A, 1000A. Each PCWS element feeds a photonic carrier signal into a PCWD 1100 through a PW or PCW connector guide. The source PS 100A with an optical fan-out of 1 provides a single-ended photonic signal through a PCWS into a termination PCWD.
(67) In embodiments of the spectrophotometer of FIG. 16, the five separate PCWS elements can be exposed to an analyte or operated as a reference without exposure to an analyte. The sources PS 100B are structured with an optical fan-out of 2 support a differential analysis of photonic carrier signals based on one or more reference analytes and analytes of interest.
(68) In the embodiment of FIG. 17, the integrated thermal sensor is configured as a spectrophotometer 1700 comprising two PCWF elements 900A to provide two separate wavelength channels into the PCWS 1750 wherein the PS provides a broadband photonic carrier signal. For example, these filtered signals delivered into the PCWS 1750 may comprise different channels providing sensitivity to different analytes. The photonic carrier signal selected by the two PCWF filters propagates through a sensor PCWS 1750 element and on into a detector PCWD 1100 element. In embodiments, the PCWFs may comprise a heater device for wavelength channel switching. In embodiments a heater device may provide outgassing for the PCWS and PCWD. The PCWF 900A and PCWD 1100 comprise thermal micro-platforms. The PCWD will typically comprise a sensitive temperature sensing device for photonic signal detection and in a preferred embodiment the PCWD comprises a Peltier thermoelectric device. In embodiments wherein may comprise a heater device modulation and a sensitive temperature sensor device for detection. In some embodiments wherein the photonic signal is in the visible or NIR wavelength range, the photonic carrier signal is detected in the PWCD with a pn junction bandgap diode.
(69) In embodiments with the spectrometer of FIG. 17, the PS photonic carrier signal is a continuous CW signal. A PCWF 900A periodically chops the photonic carrier signal to support a form of synchronous detection for improving the overall signal-to-noise level of the detected PCWD 1100 signal. This chip in embodiments provides support for implementing dual wavelength spectral analysis wherein an analyte is exposed to the PCWS 1750. In this embodiment, the detector PCWD 1100 is designed with adequate bandwidth to terminate signals from the PCWS 1750 over an adequate wavelength range.
(70) FIG. 18 depicts an embodiment wherein the integrated thermal sensor 1820 is clipped to a mobile phone 1810 with connection into the USB bus 1830 of the phone is depicted in FIG. 18. The spectrophotometer communicates with and receives DC power from the mobile phone typically through USB bus 1830. In another embodiment, the spectrometer communicates with the mobile phone through a wireless means which may include a Bluetooth or optical link.
(71) FIG. 19A depicts a plan view of a photonic source PS 1900A comprising a light emitting platform (LEP) providing a photonic carrier signal that couples into an interposer PCW 1950 through a tapered waveguide PW 1940. In this embodiment the LEP photonic source shares the same substrate with one or more of the other photonic elements. The LEP comprises a thermal micro-platform 1920 supported by nanowires of type 1980 disposed within thermal devices 1970 and 1975. The thermal micro-platform 1920 is disposed over cavity 1930 with boundary 1910 and surrounded by an off-platform support structure 1960. In embodiments, one thermal device is a resistive heater and the other thermal device is a thermistor.
(72) The thermal micro-platform 1920 is heated to provide a blackbody source of radiation which is filtered through metamaterial disposed into the thermal micro-platform. The micro-platform comprises a layered metamaterial sandwich of photonic structure comprising three layers. A first layer comprises a 2-D array of plasmonic ALD metal resonators 1902 arranged in a periodic fashion over a dielectric film 1990. These resonators couple with the thermal energy supplied by the heater to provide a photonic carrier signal of limited bandwidth exiting into tapered photonic waveguide (PC) 1940. These resonators comprise one or more of split ring resonators (SRR), surface plasmon particles (SPP), 1-D Bragg grating and LC resonant structures. These resonators concentrate electromagnetic fields according to the size and shape of the patterned ALD structure, the permittivity of the platform dielectric and temperature. In a preferred embodiment, the dielectric film 1990 is formed of the active layer of a silicon SOI wafer. In other embodiments, an ALD metal film is disposed under the dielectric film.
(73) FIG. 19B depicts a view cross-section a-a′ of emitters 1900A and 1900B from FIG. 19A depicting the released micro-platform 1920 and an underlying topside-etched cavity 1930. Micro-platform 1920 comprises the photonic resonator elements. A buried oxide (BOX) layer 1915 of a starting silicon SOI wafer is sandwiched between the device layer 1925 and a handle wafer 1935.
(74) A method for operating the integrated thermal sensor wherein the photonic elements PS, PCWF, PCWS and PCWD are configured as a spectrophotometer and wherein the operation comprises: providing a photonic signal from a photonic source (PS) within one or more wavelength bands; exposing the photonic crystal waveguide sensor (PCWS) to two analytes comprising a reference analyte and an analyte of interest, wherein obtaining signal levels from the photonic crystal waveguide detector (PCWD) comprising a first measurement of signal level based on the reference analyte and a second measurement of signal level based on the analyte of interest; defining a difference signal based on the difference in the first and second signal levels, and analyzing the differential signal to provide detection and/or monitoring of the analyte of interest.
(75) It is to be understood that although the disclosure teaches many examples of embodiments in accordance with the present teachings, many additional variations of the invention can easily be devised by those skilled in the art after reading this disclosure. As a consequence, the scope of the present invention is to be determined by the following claims.
