Showing papers on "Microheater published in 2013"

Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

Abstract: Fast-Response, Sensitivitive and Low-Powered Chemosensors by Fusing Nanostructured Porous Thin Film and IDEs-Microheater Chip

Tunable Vernier Microring Optical Filters With $p\!-\!i \!-\!p$ -Type Microheaters

Abstract: We present thermally tunable microring optical filters using p-i-p-type microheaters. The use of Vernier effect in the cascaded two microring resonators significantly enlarges the free spectral range (FSR) and the thermal tuning range with reduced power consumption. Heat generated by the p-i-p-type microheaters interacts directly with the microring waveguides, providing a means to effectively tune resonances without incurring excess loss. Experimental results reveal that the filter passband can be discretely shifted in the wavelength range from 1520 to 1600 nm by tuning one resonator with a power tuning efficiency value of 2.5 nm/mW. The passband can be also continuously shifted by simultaneously tuning both resonators with a power tuning efficiency value of 0.11 nm/mW. The rise (fall) time of the p-i-p microheater is measured to be 460 ns (1.1 μs) under a peak-to-peak driving voltage of 3.4 V.

Flexible NO 2 gas sensor using multilayer graphene films by chemical vapor deposition

Abstract: We report a highly sensitive NO2 gas sensor based on multi-layer graphene (MLG) films synthesized by a chemical vapor deposition method on a microheater-embedded flexible substrate. The MLG could detect low-concentration NO2 even at sub-ppm (<200 ppb) levels. It also exhibited a high resistance change of ~6% when it was exposed to 1 ppm NO2 gas at room temperature for 1 min. The exceptionally high sensitivity could be attributed to the large number of NO2 molecule adsorption sites on the MLG due to its a large surface area and various defect-sites, and to the high mobility of carriers transferred between the MLG films and the adsorbed gas molecules. Although desorption of the NO 2 molecules was slow, it could be enhanced by an additional annealing process using an embedded Au microheater. The outstanding mechanical flexibility of the graphene film ensures the stable sensing re sponse of the device under extreme bending stress. Our large-scale and easily reproducible MLG films can provide a proof-of-concept for future flexible NO 2 gas sensor devices.

Semiconductor-Type MEMS Gas Sensor for Real-Time Environmental Monitoring Applications

Abstract: Low power consuming and highly responsive semiconductor-type microelectromechanical systems (MEMS) gas sensors are fabricated for real-time environmental monitoring applications. This subsystem is developed using a gas sensor module, a Bluetooth module, and a personal digital assistant (PDA) phone. The gas sensor module consists of a NO2 or CO gas sensor and signal processing chips. The MEMS gas sensor is composed of a microheater, a sensing electrode, and sensing material. Metal oxide nanopowder is drop-coated onto a substrate using a microheater and integrated into the gas sensor module. The change in resistance of the metal oxide nanopowder from exposure to oxidizing or deoxidizing gases is utilized as the principle mechanism of this gas sensor operation. The variation detected in the gas sensor module is transferred to the PDA phone by way of the Bluetooth module.

Sub-100-nanosecond thermal reconfiguration of silicon photonic devices

Abstract: One of the limitations of thermal reconfiguration in silicon photonics is its slow response time. At the same time, there is a tradeoff between the reconfiguration speed and power consumption in conventional reconfiguration schemes that poses a challenge in improving the performance of microheaters. In this work, we theoretically and experimentally demonstrate that the high thermal conductivity of silicon can be exploited to tackle this tradeoff through direct pulsed excitation of the device silicon layer. We demonstrate 85 ns reconfiguration of 4 µm diameter microdisks, which is one order of magnitude improvement over the conventional microheaters. At the same time, 2.06 nm/mW resonance wavelength shift is achieved in these devices, which is in a par with the best microheater architectures optimized for low-power operation. We also present a system-level model that precisely describes the response of the demonstrated microheaters. A differentially addressed optical switch is also demonstrated that shows the possibility of switching in opposite directions (i.e., OFF-to-ON and ON-to-OFF) using the proposed reconfiguration scheme.

Vertical-coupled high-efficiency tunable III-V- CMOS SOI hybrid external-cavity laser

Abstract: We demonstrate a hybrid III-V/SOI laser by vertically coupling a III-V RSOA chip with a SOI-CMOS chip containing a tunable wavelength selective reflector We report a waveguide-coupled wall-plug-efficiency of 55% and output power of 10 mW A silicon resistor-based microheater was integrated to thermally tune a ring resonator for precise lasing wavelength control A high tuning efficiency of 22 nm/mW over a range of 18 nm was achieved by locally removing the SOI handler substrate C-band single mode lasing was confirmed with a side mode suppression ratio of 35 dB This grating coupler based vertical integration approach can be scaled up in two dimensions for efficient multi-wavelength sources in silicon photonics

Compact Thermo-Optic Switch Based on Tapered W1 Photonic Crystal Waveguide

Abstract: A compact thermo-optic switch based on the cutoff effect of slow-light mode of a tapered W1 photonic crystal waveguide (PCW) is demonstrated with an integrated microheater. Due to the low-group-index taper, the coupling loss of the slow-light PCW is reduced, and a high switching extinction ratio (ER) is attained. Moreover, three types of microheaters are evaluated for the power consumptions, heating transfer efficiency, and temperature uniformities, and an optimized slab microheater is utilized. As a result, low switching power of 8.9 mW and high ER of 23.5 dB are achieved experimentally, while the length of W1 PCW is only 16.8 μm.

$\hbox{MnO}_{2}$ Nanowire Embedded Hydrogen Peroxide Monopropellant MEMS Thruster

Abstract: Feasibility of chemically synthesized MnO2 nanowire catalyst embedded silicon microelectromechanical systems (MEMS) H2O2 monopropellant microthruster has been demonstrated. Due to exothermic reaction process, sustenance of thrust generation does not require any heating of propellant thus minimizing electrical power requirement. The thruster device integrates inlet nozzle, microchannel, MnO2 nanowire embedded reaction chamber, in-plane exit nozzle and a microheater in the silicon layer. Nozzle configuration and catalyst bed was designed using simple analytical equations to achieve complete decomposition of H2 O2 and maximum thrust force by controlling the propellant flow. Simulation of hydrogen peroxide decomposition process was carried out to evaluate the thermo-chemical characteristics. The MnO2 nanowire has been obtained using a low-cost synthesis process and characterized using field emission scanning electron microscopy, Energy-dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray diffraction studies. Thruster fabrication using micromachining process and its testing have been briefly described. The device is capable to produce 1 mN thrust and specific impulse of 180 s using 50 wt.% concentrated H2O2 of flow rate 1.25 mg/s with total ignition energy of 44 J required for preheating the catalyst bed. Detailed thrust measurement was carried out with propellant mass flow rate for different throat area of exit nozzle, and the results were interpreted with theoretical model.

Silicon on insulator thermodiode with extremely wide working temperature range

Abstract: This paper presents for the first time the performance of a silicon-on-insulator (SOI) p+-n+ thermodiode, which can operate in an extremely wide temperature range of -200 °C to 700 °C while maintaining its linearity. The thermodiode is embedded in a thin dielectric membrane underneath a tungsten microheater, which allows the diode characterization at very high temperature (> 800 °C). The effect of the junction area (Aj) on the thermodiode linearity, sensitivity and self-heating is experimentally and theoretically investigated. Results on the long-term diode stability at high temperature are also reported.

One-dimensional model of inertial pumping.

Abstract: A one-dimensional model of inertial pumping is introduced and solved. The pump is driven by a high-pressure vapor bubble generated by a microheater positioned asymmetrically in a microchannel. The bubble is approximated as a short-term impulse delivered to the two fluidic columns inside the channel. Fluid dynamics is described by a Newton-like equation with a variable mass, but without the mass derivative term. Because of smaller inertia, the short column refills the channel faster and accumulates a larger mechanical momentum. After bubble collapse the total fluid momentum is nonzero, resulting in a net flow. Two different versions of the model are analyzed in detail, analytically and numerically. In the symmetrical model, the pressure at the channel-reservoir connection plane is assumed constant, whereas in the asymmetrical model it is reduced by a Bernoulli term. For low and intermediate vapor bubble pressures, both models predict the existence of an optimal microheater location. The predicted net flow in the asymmetrical model is smaller by a factor of about 2. For unphysically large vapor pressures, the asymmetrical model predicts saturation of the effect, while in the symmetrical model net flow increases indefinitely. Pumping is reduced by nonzero viscosity, but to a different degree depending on the microheater location.

High speed DNA denaturation using microheating devices

Abstract: Denaturation is a first step for further treatment of DNA and is expected to be carried out rapidly on an integrated chip. A microheater is a promising device for the denaturation because of easiness for fabrication and operation. In the present study, we fabricated a microheater and thermometers on a coverslip and investigated response of temperature to application of voltage. In addition, our experiment and simulation proved local heating at an aimed area. Finally, we demonstrated denaturation of DNA in buffer solution, the result of which proved that the DNA around the heater denatured within 60 ms.

Thermo-optic simulations of silicon nitride / polymer hybrid waveguides

Abstract: We perform the thermal and optical simulations of silicon nitride / polymer hybrid waveguides with different heating schemes by finite element method. Both the top and buried microheaters are adopted to realize tuning function by the thermo-optic effect. We find the buried microheater is more energy-efficient than the top microheater in creating a uniformed temperature environment in the waveguide region. On the other hand, the top electrode tends to create a strong temperature gradient through the waveguide, which in turn distorts the optical mode. This distortion, however, is different for TE and TM modes. This thermally induced birefringence effect is thoroughly investigated in this paper. Keywords: Silicon nitride waveguide, polymer, microheater, bire fringence, thermal simulation, thermo-optic effect 1. INTRODUCTION Optical integration has attracted much attention worldwide, because of the compact size, cost effectiveness, improved functionalities, and so on. Planar waveguide technologies, including SOI (silicon on insulator), silica-on-silicon, III-V semiconductors, lithium niobate, and polymers, have been extensively investigated due to their potentials of providing a platform for the optical integration. Polymer materials present several advantages, such as low-cost production, fast prototyping, and versatility to incorporate other dielectric and metal materials. In addition, polymers possess both high thermo-optic coefficient and low thermal conductivity [1], wh ich makes them ideal to realize thermally tunable devices, such as variable optical attenuators [2], digital optical switches [3, 4], tunable filters [5], and so on. The thermo-optic coefficient (TOC) of polymer materials is on the order of -1.0 to -3.0 ×10

Design and evaluation of microheater combined QCM array for thermal desorption spectroscopy

Abstract: In this paper, we propose a single microheater combined quartz crystal microbalance array for thermal desorption spectroscopy. The each QCM has two electrodes for exciting thickness shear mode (TSM) vibrations on one side of the crystal and a double-spiral-shape heater on the other side. The resonance frequency is stable when a voltage was applied on the microheater. Carbon microparticles for gas adsorption were coated on one of the QCMs and the frequency change during temperature increase was extracted by subtracting the change of the other QCM. The proposed QCM array can monitor small mass changes at sub-ng level as a function of temperature.

Optimisation of low dissipation micro-hotplates - Thermo-mechanical design and characterisation

Abstract: This work describes the results of a systematic investigation of micro-hotplates on thin isolating membranes capable of operation up to 600 °C both in static and dynamic mode. For the selection of optimum device geometry and the layer structure alternatives FEM analysis was applied. The materials considered were Si3N4, SiO2, TiO2/Pt, Al2O3 and their combination in various multilayer structures. To reduce the chip size DRIE was selected for the release of the membrane. Experimental characterization of the hotplates was carried out by various techniques; the average hotplate temperature was deduced from the resistance of the applied Pt heater and verified by micro-melting point measurements. Buckling of the membranes was tested by means of optical methods and the cumulative stress of the multilayer structure quantified by Makyoh-topography. Pulsed mode cyclic heating revealed the dynamic properties and also served for accelerated stability tests. For demonstration microheater devices with heat dissipation up to 23 °C/mW and t90 <; 3ms were constructed to form the basis of combustive type gas sensors operated at elevated temperature.

Batch fabrication of micro preconcentrator with thin film microheater using Tollen's reaction

Abstract: A batch fabrication with simple micromachined process based on one photomask and the microfluidic laminar flow patterning technique is developed for a novel micropreconcentrator (μPCT) used in a micro gas chromatograph (μGC). Silver deposition using Tollens' reactions in microfludic channels provides a higher deposition rate and easier microfabrication compared to conventional micromachined technologies for thick metal microstructures (> 200 μm). An amorphous and porous carbon film that functions as an adsorbent is grown on microheaters inside the microchannel. The μPCT can be heated to >300°C rapidly by applying a constant electrical power of ~5 W with a heating rate of 60°C/s. Four volatile organic compounds (VOCs), acetone, benzene, toluene, and xylene, are collected through the proposed novel μPCTs and separated successfully using a 17-m-long gas chromatography (GC) column. Compared with our previous work, the more uniform temperature distribution, more efficient heating rate and smaller peak widths at half height (PWHH) are obtained.

Surface ionisation gas detection: Vertical versus planar readout modes

Abstract: The work is concerned with the micro-miniaturisation of surface ionisation (SI) gas sensing devices. MEMS microheaters, originally designed for the heating and readout of metal oxide (MOX) gas sensing layers, have been configured to observe SI gas sensor signals. We show that this can be performed in two distinctly different ways. In the first, vertical mode, one of the interdigital platinum (Pt) electrodes on top of the dielectric heater membrane is used as an ion emitting layer while a flat-plate counter electrode, positioned at a short distance above the emitting Pt electrode, is used for the ion current readout. In the second, planar mode, one of the two Pt interdigital electrodes is used as an ion emitter while the second serves as an ion collector. We show that both modes of readout feature ionisation efficiencies orders of magnitude larger than our previously investigated thin-film, flat plate devices. We attribute this first fact to the field enhancement that occurs at the sharp edges of Pt interdigital electrodes. Both modes of readout, however, differ considerably with regard to gas selectivity: whereas in the vertical readout mode a relatively high level of amine selectivity is observed, only a broad-range selectivity is observed in the planar mode. We conclude from this latter observation that the amine-selectivity, which is typical of SI devices, only arises when the surface–adsorbate bond needs to be broken, i.e. whenever analyte ions are forced across an air gap.

Microthermal sensors for determining fluid composition and flow rate in fluidic systems

Abstract: The analysis of fluid mixtures regarding their composition is still a major challenge, e.g. for Direct Methanol Fuel Cells (DMFC) to determine the concentration of methanol in water or for Selective Catalytic Reduction (SCR) to determine the amount of urea in water. A simple measurement method is realized with a microthermal sensor that introduces a short heat pulse into the fluid under test whilst the resulting temperature increase is measured reflecting thermal parameters of the fluid. For methanol in water this principle showed an almost linear dependence of the temperature increase on the methanol content for the concentration range 0 to 20 vol%. The sensitivity was determined to S = 0.12 K/vol% for methanol in water for a heat pulse of 0.5 s duration and a heater power of 60 mW. The accuracy achieved in single pulse measurements is approximately 2 %. By integrating additional temperature sensors in front and behind the microheater the flow rate of the liquid can also be determined using thermal anemometry. Because of the physical measurement principle to determine the chemical properties of the liquid the sensor promises better long-term stability than chemical principles. At the same time the low cost sensor construction and simple signal analysis make this principle promising for use in low cost mobile applications like DMFC power supplies for laptops.

Experimental study of temperature response of a microfiber coupler sensor with a liquid crystal overlay.

Abstract: The paper presents the results of experimental studies of the temperature dependence of a microfibre coupler (MFC) with a waist diameter of ~4 μm covered with a layer of liquid crystal (LC) material. The microfiber coupler is fabricated by fusing together and tapering of two standard telecom fibers using a microheater brushing technique, followed by partially embedding the structure in a low-refractive index UV curable polymer (Efiron PC-363) for stability and later by placing a thin heated LC layer over the polymer-free uniform taper waist region. The temperature dependence of the embedded in polymer MFC sensor before the application of the LC layer demonstrates a redshift of the coupler’s spectrum with an average sensitivity of ~0.5 nm/°C in the temperature range of 14-70 °C. The application of the LC overlay increases the average temperature sensitivity to ~0.7 nm/°C. The demonstrated device offers several advantages such as ease of fabrication and light coupling, the potential for better stability and the possibility of electric field tuning for realizing temperature, electric field, bio-, chemical sensors and tunable add-drop filters for fiber communication systems. Further work is ongoing to explore various tuning mechanisms of the MFC spectrum.

Versatile graphene nanocomposite microheater patterning for various thermoplastic substrates based on capillary filling and transfer molding

Abstract: We report a fabrication method of graphene nanocomposite patterns on a thermoplastic substrate using capillary filling and transfer molding techniques. As a proof of concept, we produced microheaters using a low-viscosity graphene nanocomposite solution. After filling a microchannel on a polydimethylsiloxane (PDMS) stamp with graphene solution, the solution solvent was evaporated, leaving behind the graphene nanocomposite pattern. Subsequent embossing of the graphene nanocomposite patterns on the PDMS stamp onto a polymethylmethacrylate substrate allowed the transfer of the microheater pattern. Capillary filling was characterized analytically and experimentally. The performance and thermal response of the fabricated microheater were very promising.

Carbon Nanotube based heat-sink for solid state lighting

Abstract: A new carbon-nanotube-based (CNTs) heat sink is developed. Due to their high thermal conductivity and aspect ratio, CNT boundles are used as fins of the heat sink. Fins as high as 300 μm with an aspect ratio of 30 are fabricated. For the thermal characterization of the heat sink, a microheater is integrated with the heat-sink and it is also used as temperature sensor. It is realized by using the low doped silicon bulk as electrical resistor. The sensor shows a sensitivity of 0.6 Ω/K. A thermal characterization is performed to evaluate the heat dissipated by the CNT-based heat-sink. Results show that up to 18% of power reduction can be achieved with the proposed CNTs-based heat-sink configuration.

Volatile organic compounds sensor with stacked interdigitated electrodes coated with monolayer-protected gold nanoclusters

Abstract: In this paper we present a complementary metal-oxide-semiconductor (CMOS) based volatile organic compounds (VOCs) sensor featured by stacked interdigitated electrodes and a polysilicon microheater. N-octanethiol functionalized gold nanoparticles (Au-C8), a type of monolayer-protected gold nanoclusters (MPCs), were employed as sensing material. The design of the sensor and the fabrication utilizing a commercial CMOS process were demonstrated. MPCs were coated by airbrushing MPCs suspension and simultaneous heating was provided by the on-chip microheater. The sensor performance was tested using octane, toluene and butanol. The responses were fast, and the sensitivity, defined as the ratio of resistance change rate (ppm) to gas concentration (ppm), was 33.1, 27.6 and 21.9 ppm/ppm for octane, toluene and butanol, respectively. Being a universal detector implicated its applicability to a gas chromatograph.

Broadband thermo-optic switch based on a W2 photonic crystal waveguide

Abstract: Broadband thermo-optic switch based on an ultra-compact W2 photonic crystal waveguide (PCW) is demonstrated with an integrated titanium/aluminum microheater on its surface. The operating principle relies on shifting a transmission-dip caused by the enhanced coupling between the defect modes in W2 PCW. As a result, broadband switching functionality with larger extinction ratio can be attained. Moreover, microheaters with different width are evaluated by the power consumptions and heating transfer efficiency, and an optimized slab microheater is utilized. Finally, switching functionality with bandwidth up to 24 nm (1557~1581 nm) is measured by the PCW with footprint of only 8μm×17.6 μm, while the extinction ratio is in excess of 15 dB over the entire bandwidth. What’s more, the switching speed is obtained by the measurement of alternating current modulation. Response time for this thermo-optic switch is 11.0±3.0 μs for rise time and 40.3±5.3 μs for fall time, respectively.

Fabrication of thermoresponsive gel blocks using hysteresis towards cell assembly

Abstract: In this paper, we propose a new method to assemble microstructures made of a thermoresponsive gel using hysteresis character of the thermoresponsive polymer solution. This method can be used for 3 dimensional cell assembly by embedding cells in the thermoresponsive gel structures. Gel blocks can be maintained the gel condition by the hysteresis character and the microstructures can be formed by assembling the gel blocks. The temperature distribution around a microheater was analyzed to generate the thermoresponsive gel and avoid thermal damages to cells. The generation of thermoresponsive gel was conducted using the microheater which was embedded in a probe tip and manipulated by a micromanipulator. The fabrication of a gel block was achieved using the hysteresis character and the fabricated gel block was picked and placed by the probe. Cells were embedded in the gel by controlling the position of microheater to avoid the influence of thermal convection flow. The positioning of the gel blocks can be precisely controlled by the micromanipulator. The results indicate the method we propose has a great possibility to achieve 3D cell assembly without large stress to cells during the assembly and cell culture.

Obtaining Highly Selective Responses from a Bulk Tin Oxide Gas Sensor

Abstract: Generic gas sensors are commonly used for the detection of different airborne contaminants due to their high sensitivity, long life and low cost, but they generally suffer from the variety of drifts and the lack of selectivity. Different techniques have been developed for selectivity enhancement in metal oxide gas sensors, among which operating temperature modulation is well known. It has been observed that sharp pallet temperature changes provide more analyte-related information. Due to the high thermal capacitance of the device, applying step voltage pulses to a bulk tin oxide gas sensor fails to provide step pallet temperature variations. On the other hand, the low thermal capacity of the custom made microheater gas sensors renders them vulnerable to all kinds of thermal noise and agitations. A novel technique is reported for temperature modulation, which facilitates sharp temperature rises of the gas sensitive pallets in generic gas sensors [. In this technique, a sharp heating voltage spike, considerably surpassing the nominal heating voltage, is applied prior to each heating voltage step. The thermal impact of these spikes is adjusted by controlling v2dt for obtaining the closest variations to the ideal temperature profile. Here, the advantages and effectiveness of the technique are demonstrated by differentiating among iso-butanol, tert-butanol, 1-butanol and 2-butanol contaminations in a wide concentration range in air using only a single generic tin oxide gas sensor.

Limiting current gas sensor, method for producing limiting current gas sensor, and sensor network system

Abstract: This limiting current gas sensor is provided with: an Si substrate (1); a microheater (2) formed on the Si substrate (1); a solid electrolyte layer (4) having ion conductivity formed on the Si substrate (1); a positive-negative pair of porous electrodes (5a, 5b) formed adhered to the solid electrolyte layer (4); and a detection circuit (8) for detecting a predetermined gas concentration in a gas to be measured by means of a limiting current method by means of imposing a voltage between the positive-negative pair of porous electrodes (5a, 5b). Provided are: the limiting current gas sensor, which is able to reduce power consumption; a method for producing the limiting current gas sensor; and a sensor network system.

Development of Accelerated Method for Thermal Cycling in Electronic Packaging Application

Abstract: The method is based on a microheater integrated next to a wire bonding pad (testpad) on a test chip. It is fabricated in CMOS technology without additional micromachining. The microheater consists of two polysilicon resistor elements, placed at opposite sides of the pad, operated in parallel using a constant voltage, each element extending over 30 x 70 µm with a resistance of ≈140 Ohm at room temperature, and is operated based on Joule heating. The polysilicon is located at least 20 µm but not more than 50 µm from the pad aluminum. To characterize the microheater, Al serpentine resistors are placed on and between the heaters next to the pad, serving as resistive temperature detectors, having resistances of about 9.4 Ohm at room temperature. With a constant operation voltage of 15 V, ≈140 mA of current and ≈2.1 W of heating power are generated, resulting in a heat flux of ≈500 MW/m 2 . The thermal resistance of the heater is 200 K/W (i.e. loss coefficient of 5 mW/K). The maximum temperature measured on one of the microheater resistors was above 396 oC and was reached using 18 V within less than 5 s of voltage application starting at room temperature. When heating from 101 oC to 138 oC, even faster heating is possible, allowing to perform highly accelerated thermocycles. These cycles are applied to a ball bond on the test pad. Compared to the 20 min cycles used by a standard test, the new microheater device performed cycles lasting 10 ms (5 ms on, 5 ms off) which is five orders of magnitude faster. The released energy is typically 10 mJ per cycle. A 50 µm diameter ball was made using 25 µm diameter Au wire and bonded to the test pad. The effect of the microheater-cycling on the contact resistance values of ball bonds is described. Starting with typical contact resistance values around 2.5 mOhm, the increase observed is between 4 % and 7 % after 5 million 10 ms cycles (≈14 h).

Surface plasmon polariton based wavelength selective IR emitter combined with microheater

Abstract: A newly proposed surface plasmon polariton (SPP) based wavelength selective IR emitter is combined with microheater. The excited SPP propagates on the metallic grating carrying IR having the wavelength near to the grating pitch. By confining IR having other wavelength inside the cavity, the thermal emission is controlled. Emission peak at the wavelength near to the period of the grating is observed. Since the microheater can minimize the loss due to the thermal conduction from the high temperature region to the surrounding basement, the energy efficiently is expected.

Fabrication of polymer Fabry-Perot fiber sensors using optical fiber microheaters

Abstract: We report on a novel fabrication technique for polymer based Fabry-Perot (F-P) optical fiber sensors. The F-P interferometers are based on microbubbles generated in the polymer by means of a microheater fiber probe. Upon inserting the probe and a cleaved single-mode fiber in a capillary tube containing the polymer, a microbubble can be readily generated which can serve as a reflective surface. A F-P cavity is thus formed by the microbubble and the single-mode fiber tip and temperature or strain deforming the bubble can be detected upon monitoring the FP resonances. The fabrication and performance of these devices as a temperature sensor is presented in this paper.