G. Gruetzner, Jan J. Klein, M. Vogler, A. Schleunitz
Advanced micro- and nanofabrication processes are constantly evolving from academic R&D environment towards real production technology. Therefore, the availability of suitable polymers for optical applications plays a crucial role to satisfy not only application based requirements but also the compatibility to industrial production technologies. In this context, UV-curable hybrid polymers, i.e. inorganic-organic materials obtained by sol-gel chemistry, were recently implemented into mass production environment, e.g. for micro-lenses in mobile device applications. In this contribution, we report on the development of innovative hybrid polymers and their tailoring towards an easy and fast processing with reliable and reproducible performance output for industrial large-scale production. Based on a discussion on standard process parameters with respect to optimize the material’s performance, the technical demands of industrial manufacture to the hybrid polymers will be subsequently reviewed by giving selective examples. This will be complemented by a brief description of current R&D activities adapting hybrid polymers to future patterning technologies.
{"title":"UV-curable hybrid polymers for optical applications: technical challenges, industrial solutions, and future developments","authors":"G. Gruetzner, Jan J. Klein, M. Vogler, A. Schleunitz","doi":"10.1117/12.2043038","DOIUrl":"https://doi.org/10.1117/12.2043038","url":null,"abstract":"Advanced micro- and nanofabrication processes are constantly evolving from academic R&D environment towards real production technology. Therefore, the availability of suitable polymers for optical applications plays a crucial role to satisfy not only application based requirements but also the compatibility to industrial production technologies. In this context, UV-curable hybrid polymers, i.e. inorganic-organic materials obtained by sol-gel chemistry, were recently implemented into mass production environment, e.g. for micro-lenses in mobile device applications. In this contribution, we report on the development of innovative hybrid polymers and their tailoring towards an easy and fast processing with reliable and reproducible performance output for industrial large-scale production. Based on a discussion on standard process parameters with respect to optimize the material’s performance, the technical demands of industrial manufacture to the hybrid polymers will be subsequently reviewed by giving selective examples. This will be complemented by a brief description of current R&D activities adapting hybrid polymers to future patterning technologies.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"162 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114603975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Andilla, Omar E. Olarte, R. Aviles-Espinosa, P. Loza-Álvarez
Acquisition of images deep inside large samples is one of the most demanded improvements that current biology applications ask for. Absorption, scattering and optical aberrations are the main difficulties encountered in these types of samples. Adaptive optics has been imported form astronomy to deal with the optical aberrations induced by the sample. Nonlinear microscopy and SPIM have been proposed as interesting options to image deep into a sample. Particularly, light-sheet microscopy, due to its low photo bleaching properties, opens new opportunities to obtain information for example in long time lapses for large 3D imaging. In this work, we perform an overview of the application of adaptive optics to the fluorescence microscopy in linear and non-linear modalities. Then we will focus in the light-sheet microscopy architecture of two orthogonal optical paths which implies new requirements in terms of optical correction. We will see the different issues that appear in light-sheet microscopy particularly when imaging large and non-flat samples. Finally, we will study the problem of the isoplanetic patches.
{"title":"Imaging deep and clear in thick inhomogeneous samples","authors":"J. Andilla, Omar E. Olarte, R. Aviles-Espinosa, P. Loza-Álvarez","doi":"10.1117/12.2041448","DOIUrl":"https://doi.org/10.1117/12.2041448","url":null,"abstract":"Acquisition of images deep inside large samples is one of the most demanded improvements that current biology applications ask for. Absorption, scattering and optical aberrations are the main difficulties encountered in these types of samples. Adaptive optics has been imported form astronomy to deal with the optical aberrations induced by the sample. Nonlinear microscopy and SPIM have been proposed as interesting options to image deep into a sample. Particularly, light-sheet microscopy, due to its low photo bleaching properties, opens new opportunities to obtain information for example in long time lapses for large 3D imaging. In this work, we perform an overview of the application of adaptive optics to the fluorescence microscopy in linear and non-linear modalities. Then we will focus in the light-sheet microscopy architecture of two orthogonal optical paths which implies new requirements in terms of optical correction. We will see the different issues that appear in light-sheet microscopy particularly when imaging large and non-flat samples. Finally, we will study the problem of the isoplanetic patches.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127112852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Schwarz, H. E. Williams, C. Grabill, A. M. Lewis, S. Kuebler, Benn Gleason, K. Richardson, A. Pogrebnyakov, T. Mayer, C. Drake, C. Rivero‐Baleine
Arsenic trisulfide (As2S3) is a transparent material from ~620 nm to 11 μm with direct applications in sensors, photonic waveguides, and acousto-optics. As2S3 may be thermally deposited to form glassy films of molecular chalcogenide (ChG) clusters. It has been shown that linear and multi-photon exposure can be used to photo-pattern thermally deposited As2S3. Photo-exposure cross-links the film into a network solid. Treating the photo-patterned material with a polarsolvent removes the unexposed material leaving behind a structure that is a negative-tone replica of the photo-pattern. In this work, nano-structure arrays were photo-patterned in As2S3 films by multi-photon direct laser writing (DLW) and the resulting structure, morphology, and chemical composition were characterized and correlated with the conditions of the thermal deposition, patterned irradiation, and etch processing. Raman spectroscopy was used to characterize the chemical structure of the unexposed and photo-exposed material, and near infrared ellipsometry was used to measure the refractive index. Physical characterization including structure size and surface adhesion of nano-scale features is related to the processing conditions.
{"title":"Processing and properties of arsenic trisulfide chalcogenide glasses for direct laser writing of 3D microstructures","authors":"C. Schwarz, H. E. Williams, C. Grabill, A. M. Lewis, S. Kuebler, Benn Gleason, K. Richardson, A. Pogrebnyakov, T. Mayer, C. Drake, C. Rivero‐Baleine","doi":"10.1117/12.2042809","DOIUrl":"https://doi.org/10.1117/12.2042809","url":null,"abstract":"Arsenic trisulfide (As2S3) is a transparent material from ~620 nm to 11 μm with direct applications in sensors, photonic waveguides, and acousto-optics. As2S3 may be thermally deposited to form glassy films of molecular chalcogenide (ChG) clusters. It has been shown that linear and multi-photon exposure can be used to photo-pattern thermally deposited As2S3. Photo-exposure cross-links the film into a network solid. Treating the photo-patterned material with a polarsolvent removes the unexposed material leaving behind a structure that is a negative-tone replica of the photo-pattern. In this work, nano-structure arrays were photo-patterned in As2S3 films by multi-photon direct laser writing (DLW) and the resulting structure, morphology, and chemical composition were characterized and correlated with the conditions of the thermal deposition, patterned irradiation, and etch processing. Raman spectroscopy was used to characterize the chemical structure of the unexposed and photo-exposed material, and near infrared ellipsometry was used to measure the refractive index. Physical characterization including structure size and surface adhesion of nano-scale features is related to the processing conditions.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124829535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Warashina, Tomofumi Suzuki, Kohei Kasamori, Ryosuke Okumura, Yuki Matsuo, M. Takemura
A MEMS-FTIR engine has been developed as a key device for the Fourier-Transform Infrared Spectrometer, which consists of a Michelson interferometer including an electro-static actuator to control a moving mirror, an optical fiber groove for incident light and a photodetector. All these elements except for the photodetector are monolithically fabricated in Silicon using MEMS technology. The optical elements such as a beam splitter, a fixed mirror and a moving mirror are formed and aligned simultaneously with high degree of precision by Deep Reactive Ion Etching (DRIE). The vertical side walls are utilized as optical planes so that the incident light path is located in parallel with the Silicon substrate. The moving mirror is driven by an electro-static MEMS actuator. The photodetector is placed above an angled mirror, which is formed by alkaline wet etching exposing the Silicon crystal plane at the end position of light path. All the elements including the photodetector are hermetically covered by a lid of Silicon in the vacuum chamber by using a surface activate bonding technology. In order to reduce the cost, wafer level process and separation of each chip by a laser dicer after all assembly processes are introduced. The realized MEMS-FTIR is 10×17×1 mm in size and a signal noise ratio (SNR) of better than 35dB, which comes from a good verticality of less than 0.2 degree in the vertical side walls as optical planes by managing the DRIE etching conditions.
MEMS-FTIR发动机是傅里叶变换红外光谱仪的关键器件，它由迈克尔逊干涉仪组成，该干涉仪包括控制运动镜的静电致动器、入射光的光纤槽和光电探测器。除了光电探测器外，所有这些元件都是使用MEMS技术在硅上单片制造的。采用深度反应离子蚀刻(Deep Reactive Ion Etching, DRIE)技术，以高精度同时形成分束器、固定反射镜和移动反射镜等光学元件。垂直侧壁被用作光学平面，使得入射光路与硅衬底平行。移动镜由静电MEMS致动器驱动。光电探测器放置于光路末端位置的硅晶体平面通过碱性湿蚀刻形成的角度反射镜上方。通过表面激活键合技术，将包括光电探测器在内的所有元件密封地覆盖在真空室中的硅盖上。为了降低成本，介绍了晶圆级工艺和在所有组装过程后用激光切割机将每个芯片分离。所实现的MEMS-FTIR尺寸为10×17×1 mm，信噪比(SNR)优于35dB，这得益于通过控制DRIE蚀刻条件，垂直侧壁作为光学平面具有小于0.2度的良好垂直度。
{"title":"MEMS based miniature FT-IR engine with built-in photodetector","authors":"Y. Warashina, Tomofumi Suzuki, Kohei Kasamori, Ryosuke Okumura, Yuki Matsuo, M. Takemura","doi":"10.1117/12.2038588","DOIUrl":"https://doi.org/10.1117/12.2038588","url":null,"abstract":"A MEMS-FTIR engine has been developed as a key device for the Fourier-Transform Infrared Spectrometer, which consists of a Michelson interferometer including an electro-static actuator to control a moving mirror, an optical fiber groove for incident light and a photodetector. All these elements except for the photodetector are monolithically fabricated in Silicon using MEMS technology. The optical elements such as a beam splitter, a fixed mirror and a moving mirror are formed and aligned simultaneously with high degree of precision by Deep Reactive Ion Etching (DRIE). The vertical side walls are utilized as optical planes so that the incident light path is located in parallel with the Silicon substrate. The moving mirror is driven by an electro-static MEMS actuator. The photodetector is placed above an angled mirror, which is formed by alkaline wet etching exposing the Silicon crystal plane at the end position of light path. All the elements including the photodetector are hermetically covered by a lid of Silicon in the vacuum chamber by using a surface activate bonding technology. In order to reduce the cost, wafer level process and separation of each chip by a laser dicer after all assembly processes are introduced. The realized MEMS-FTIR is 10×17×1 mm in size and a signal noise ratio (SNR) of better than 35dB, which comes from a good verticality of less than 0.2 degree in the vertical side walls as optical planes by managing the DRIE etching conditions.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121687856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. V. Olesen, J. Wilm, R. Paulsen, L. Højgaard, R. Larsen
In this paper we present a novel sensing system, robust Near-infrared Structured Light Scanning (NIRSL) for three-dimensional human model scanning application. Human model scanning due to its nature of various hair and dress appearance and body motion has long been a challenging task. Previous structured light scanning methods typically emitted visible coded light patterns onto static and opaque objects to establish correspondence between a projector and a camera for triangulation. In the success of these methods rely on scanning objects with proper reflective surface for visible light, such as plaster, light colored cloth. Whereas for human model scanning application, conventional methods suffer from low signal to noise ratio caused by low contrast of visible light over the human body. The proposed robust NIRSL, as implemented with the near infrared light, is capable of recovering those dark surfaces, such as hair, dark jeans and black shoes under visible illumination. Moreover, successful structured light scan relies on the assumption that the subject is static during scanning. Due to the nature of body motion, it is very time sensitive to keep this assumption in the case of human model scan. The proposed sensing system, by utilizing the new near-infrared capable high speed LightCrafter DLP projector, is robust to motion, provides accurate and high resolution three-dimensional point cloud, making our system more efficient and robust for human model reconstruction. Experimental results demonstrate that our system is effective and efficient to scan real human models with various dark hair, jeans and shoes, robust to human body motion and produces accurate and high resolution 3D point cloud.
{"title":"DLP technology application: 3D head tracking and motion correction in medical brain imaging","authors":"O. V. Olesen, J. Wilm, R. Paulsen, L. Højgaard, R. Larsen","doi":"10.1117/12.2035374","DOIUrl":"https://doi.org/10.1117/12.2035374","url":null,"abstract":"In this paper we present a novel sensing system, robust Near-infrared Structured Light Scanning (NIRSL) for three-dimensional human model scanning application. Human model scanning due to its nature of various hair and dress appearance and body motion has long been a challenging task. Previous structured light scanning methods typically emitted visible coded light patterns onto static and opaque objects to establish correspondence between a projector and a camera for triangulation. In the success of these methods rely on scanning objects with proper reflective surface for visible light, such as plaster, light colored cloth. Whereas for human model scanning application, conventional methods suffer from low signal to noise ratio caused by low contrast of visible light over the human body. The proposed robust NIRSL, as implemented with the near infrared light, is capable of recovering those dark surfaces, such as hair, dark jeans and black shoes under visible illumination. Moreover, successful structured light scan relies on the assumption that the subject is static during scanning. Due to the nature of body motion, it is very time sensitive to keep this assumption in the case of human model scan. The proposed sensing system, by utilizing the new near-infrared capable high speed LightCrafter DLP projector, is robust to motion, provides accurate and high resolution three-dimensional point cloud, making our system more efficient and robust for human model reconstruction. Experimental results demonstrate that our system is effective and efficient to scan real human models with various dark hair, jeans and shoes, robust to human body motion and produces accurate and high resolution 3D point cloud.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130361112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The increase in efficiency and precision in the production of semiconductor structures under the use of polymeric materials like SU-8 is crucial in securing the technological innovation within this industry. The manufacturing of structures on wafers demands a high quality of materials, tools and production processes. In particular, deviations in the materials' parameters (e.g. cross-linking state, density or mechanical properties) could lead to subsequent problems such as a reduced lifetime of structures and systems. In particular problems during the soft and post-exposure bake process can lead to an inhomogeneous distribution of material properties. This paper describes a novel approach for the characterization of SU-8 material properties in relation to a second epoxy-based material of different cross-linking by the measurement of optical dispersion within the material. A white-light interferometer was used. In particular the setup consisted of a white-light source, a Michelson-type interferometer and a spectrometer. The investigation of the dispersion characteristics was carried out by the detection of the equalization wavelength for different positions of the reference arm in a range from 400 to 900 nm. The measured time delay due to dispersion ranges from 850 to 1050 ps/m. For evaluation purposes a 200μm SU-8 sample was characterized in the described setup regarding its dispersion characteristics in relation to bulk epoxy material. The novel measurement approach allowed a fast and high-resolution material characterization for SU-8 micro structures which was suitable for integration in production lines. The outlook takes modifications of the experimental setup regarding on-wafer measurements into account.
{"title":"Investigation of a novel approach for the cross-linking characterization of SU-8 photoresist materials by means of optical dispersion measurements","authors":"C. Taudt, T. Baselt, E. Koch, P. Hartmann","doi":"10.1117/12.2039052","DOIUrl":"https://doi.org/10.1117/12.2039052","url":null,"abstract":"The increase in efficiency and precision in the production of semiconductor structures under the use of polymeric materials like SU-8 is crucial in securing the technological innovation within this industry. The manufacturing of structures on wafers demands a high quality of materials, tools and production processes. In particular, deviations in the materials' parameters (e.g. cross-linking state, density or mechanical properties) could lead to subsequent problems such as a reduced lifetime of structures and systems. In particular problems during the soft and post-exposure bake process can lead to an inhomogeneous distribution of material properties. This paper describes a novel approach for the characterization of SU-8 material properties in relation to a second epoxy-based material of different cross-linking by the measurement of optical dispersion within the material. A white-light interferometer was used. In particular the setup consisted of a white-light source, a Michelson-type interferometer and a spectrometer. The investigation of the dispersion characteristics was carried out by the detection of the equalization wavelength for different positions of the reference arm in a range from 400 to 900 nm. The measured time delay due to dispersion ranges from 850 to 1050 ps/m. For evaluation purposes a 200μm SU-8 sample was characterized in the described setup regarding its dispersion characteristics in relation to bulk epoxy material. The novel measurement approach allowed a fast and high-resolution material characterization for SU-8 micro structures which was suitable for integration in production lines. The outlook takes modifications of the experimental setup regarding on-wafer measurements into account.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124680896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We report on the development of a net flux radiometer as part of a wireless sensor network for the acquisition of surface meteorological data on Mars. The radiometer makes use of four separate sensors to measure simultaneously: (i) global solar radiation; (ii) ground reflected solar radiation; (iii) sky emitted infrared radiation; and (iv) ground emitted infrared radiation. To perform measurements in the broad spectral range from 0.2 to 50 μm, goldblack coated microbolometers of 100 um size were fabricated for use in custom packaged pyranometers and pyrgeometers. Each microbolometer was placed at the center of an optically coated dome which provided a field-of-view of 180° and acted as a bandpass filter. Under nominal operating conditions the microbolometer showed a responsivity of ~ 75 kV/W and a time constant of ~ 13 ms. Parametric characterization of the radiometer provided a set of bias voltages, integration time, and temperature set points that help prevent the issue of output saturation in field operation conditions. The measured sensitivity, in the range from 2 to 6 mV/(W/m2), and measured resolution, from 0.06 to 0.15 W/m2, compared favorably with those of commercial net flux instruments. The results obtained in the field operation confirmed that the temporal responses of the pyranometer and pyrgeometer are in good agreement with the responses of the commercial instrument. However, a signal drift was observed, mostly in the pyrgeometer data, over a long period acquisition. This drift, which appears to be in correlation with changes in the environment temperature, is believed to be a result of the dome heating effect.
{"title":"Design and fabrication of net flux radiometers for Mars exploration","authors":"C. Proulx, L. Ngo Phong, F. Châteauneuf","doi":"10.1117/12.2040030","DOIUrl":"https://doi.org/10.1117/12.2040030","url":null,"abstract":"We report on the development of a net flux radiometer as part of a wireless sensor network for the acquisition of surface meteorological data on Mars. The radiometer makes use of four separate sensors to measure simultaneously: (i) global solar radiation; (ii) ground reflected solar radiation; (iii) sky emitted infrared radiation; and (iv) ground emitted infrared radiation. To perform measurements in the broad spectral range from 0.2 to 50 μm, goldblack coated microbolometers of 100 um size were fabricated for use in custom packaged pyranometers and pyrgeometers. Each microbolometer was placed at the center of an optically coated dome which provided a field-of-view of 180° and acted as a bandpass filter. Under nominal operating conditions the microbolometer showed a responsivity of ~ 75 kV/W and a time constant of ~ 13 ms. Parametric characterization of the radiometer provided a set of bias voltages, integration time, and temperature set points that help prevent the issue of output saturation in field operation conditions. The measured sensitivity, in the range from 2 to 6 mV/(W/m2), and measured resolution, from 0.06 to 0.15 W/m2, compared favorably with those of commercial net flux instruments. The results obtained in the field operation confirmed that the temporal responses of the pyranometer and pyrgeometer are in good agreement with the responses of the commercial instrument. However, a signal drift was observed, mostly in the pyrgeometer data, over a long period acquisition. This drift, which appears to be in correlation with changes in the environment temperature, is believed to be a result of the dome heating effect.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129687228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The suspended MEMS structure is suitable for reducing the energy loss due to the thermal conduction. There is the possibility that IR photon energy can be well-controlled to generate some physical effects. A new method bases on the nonlinear oscillation for the detector. The thin film torsional spring exhibits a large hard spring effect when the deflection occurs in the out-of-plane direction of the film. When IR is absorbed, the resonator bends due to the thermal expansion. The torsional spring becomes harder increasing the resonant frequency. The frequency measurement is suited for the precise sensing. The device response is measured using the laser (wavelength of 650nm). The resonant frequency is 88-94kHz. Q factor is about 1600 in vacuum (1Pa). The sensitivity is -0.144[kHz/(kW/m2)]. As for the emitter, nondispersive IR gas sensor is considered. The molecules have their intrinsic absorptions. CO2 absorbs the wavelength 4.2- 4.3μm. The major incandescent light bulbs have the broad spectrum emitting IR which is not used for gas sensing. The wavelength selectivity at the gas bandwidth will improve the efficiency. A new principle uses the microheater placed facing to the grating. SPP is excited carrying IR energy on the grating surface. IR emission is the reverse process of excitation occurring at the output end. The emission spectra show SPP related peak having the width of 190nm. When the input power increases from 0.3 to 1.9W, the peak at wavelength of 3.5μm becomes clearer.
{"title":"MEMS infrared approaches to detector based on nonlinear oscillation and wavelength selective emitter using surface plasmon polariton","authors":"M. Sasaki, S. Kumagai","doi":"10.1117/12.2044314","DOIUrl":"https://doi.org/10.1117/12.2044314","url":null,"abstract":"The suspended MEMS structure is suitable for reducing the energy loss due to the thermal conduction. There is the possibility that IR photon energy can be well-controlled to generate some physical effects. A new method bases on the nonlinear oscillation for the detector. The thin film torsional spring exhibits a large hard spring effect when the deflection occurs in the out-of-plane direction of the film. When IR is absorbed, the resonator bends due to the thermal expansion. The torsional spring becomes harder increasing the resonant frequency. The frequency measurement is suited for the precise sensing. The device response is measured using the laser (wavelength of 650nm). The resonant frequency is 88-94kHz. Q factor is about 1600 in vacuum (1Pa). The sensitivity is -0.144[kHz/(kW/m2)]. As for the emitter, nondispersive IR gas sensor is considered. The molecules have their intrinsic absorptions. CO2 absorbs the wavelength 4.2- 4.3μm. The major incandescent light bulbs have the broad spectrum emitting IR which is not used for gas sensing. The wavelength selectivity at the gas bandwidth will improve the efficiency. A new principle uses the microheater placed facing to the grating. SPP is excited carrying IR energy on the grating surface. IR emission is the reverse process of excitation occurring at the output end. The emission spectra show SPP related peak having the width of 190nm. When the input power increases from 0.3 to 1.9W, the peak at wavelength of 3.5μm becomes clearer.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130007687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Bandi, X. Maeder, A. Dommann, H. Shea, A. Neels
The mechanical stability of silicon MEMS dies is strongly influenced by the microfabrication processes, especially grinding, dicing and etching, which leave characteristic damage (defects, cracks, dislocations…) in the substrate material. Specially designed mechanical tests are used to assess the resistance of micro-structures to monotonic and cyclic loading. We report on the development progress of a micromechanical test bench for reliability assessment of microstructures in 2-, 3- and 4-point bending configurations. Strain distributions and defects in micron-sized silicon devices can be investigated by in-situ testing in combination with high-resolution x-ray diffraction measurements for experimentally assessing the strain distribution.
{"title":"Improved test setup for MEMS mechanical strength investigations and fabrication process qualification","authors":"T. Bandi, X. Maeder, A. Dommann, H. Shea, A. Neels","doi":"10.1117/12.2044212","DOIUrl":"https://doi.org/10.1117/12.2044212","url":null,"abstract":"The mechanical stability of silicon MEMS dies is strongly influenced by the microfabrication processes, especially grinding, dicing and etching, which leave characteristic damage (defects, cracks, dislocations…) in the substrate material. Specially designed mechanical tests are used to assess the resistance of micro-structures to monotonic and cyclic loading. We report on the development progress of a micromechanical test bench for reliability assessment of microstructures in 2-, 3- and 4-point bending configurations. Strain distributions and defects in micron-sized silicon devices can be investigated by in-situ testing in combination with high-resolution x-ray diffraction measurements for experimentally assessing the strain distribution.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133346024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper discusses research being conducted on aluminum nitride (AlN) as a pyroelectric material for use in detecting applications. AlN is being investigated because of its high pyroelectric coefficient, thermal stability, and high Curie temperature. In order to determine suitability of the pyroelectric properties of AlN for use as a detector, testing of several devices was conducted. These devices were fabricated using microelectromechanical systems (MEMS) fabrication processes; the devices were also designed to allow for voltage and current measurements. The deposited AlN films used were 150 nm – 300 nm in thickness. Thin-films were used to rapidly increase the temperature response after the thermal stimulus was applied to the pyroelectric material. This is important because the pyroelectric effect is directly proportional to the rate of temperature change. The design used was a face-electrode bridge that provides thermal isolation which minimizes heat loss to the substrate, thereby increasing operation frequency of the pyroelectric device. A thermal stimulus was applied to the pyroelectric material and the response was measured across the electrodes. A thermal imaging camera was used to monitor the changes in temperature. Throughout the testing process, the annealing temperatures, type of layers, and thicknesses were also varied. These changes resulted in improved MEMS designs, which were fabricated to obtain an optimal design configuration for achieving a high pyroelectric response. A pyroelectric voltage response of 38.9 mVp-p was measured without filtering, 12.45 mVp-p was measured in the infrared (IR) region using a Si filter, and 6.38 mVp-p was measured in the short wavelength IR region using a long pass filter. The results showed that AlN’s pyroelectric properties can be used in detecting applications.
{"title":"Optimal microelectromechanical systems (MEMS) device for achieving high pyroelectric response of AlN","authors":"Bemnnet Kebede, R. Coutu, L. Starman","doi":"10.1117/12.2037386","DOIUrl":"https://doi.org/10.1117/12.2037386","url":null,"abstract":"This paper discusses research being conducted on aluminum nitride (AlN) as a pyroelectric material for use in detecting applications. AlN is being investigated because of its high pyroelectric coefficient, thermal stability, and high Curie temperature. In order to determine suitability of the pyroelectric properties of AlN for use as a detector, testing of several devices was conducted. These devices were fabricated using microelectromechanical systems (MEMS) fabrication processes; the devices were also designed to allow for voltage and current measurements. The deposited AlN films used were 150 nm – 300 nm in thickness. Thin-films were used to rapidly increase the temperature response after the thermal stimulus was applied to the pyroelectric material. This is important because the pyroelectric effect is directly proportional to the rate of temperature change. The design used was a face-electrode bridge that provides thermal isolation which minimizes heat loss to the substrate, thereby increasing operation frequency of the pyroelectric device. A thermal stimulus was applied to the pyroelectric material and the response was measured across the electrodes. A thermal imaging camera was used to monitor the changes in temperature. Throughout the testing process, the annealing temperatures, type of layers, and thicknesses were also varied. These changes resulted in improved MEMS designs, which were fabricated to obtain an optimal design configuration for achieving a high pyroelectric response. A pyroelectric voltage response of 38.9 mVp-p was measured without filtering, 12.45 mVp-p was measured in the infrared (IR) region using a Si filter, and 6.38 mVp-p was measured in the short wavelength IR region using a long pass filter. The results showed that AlN’s pyroelectric properties can be used in detecting applications.","PeriodicalId":395835,"journal":{"name":"Photonics West - Micro and Nano Fabricated Electromechanical and Optical Components","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2014-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132238614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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