A. Nikitin, J. Sheldakova, A. Kudryashov, G. Borsoni, D. Denisov, V. Karasik, A. Sakharov
In this paper we consider two approaches widely used in testing of wide aperture optics: Fizeau interferometer and Shack-Hartmann wavefront sensor. Fizeau interferometer that is common instrument in optical testing can be transformed to a device using Shack-Hartmann wavefront sensor, the alternative technique to check wide aperture optical components. We call this device Hartmannometer, and compare its features to those of Fizeau interferometer.
{"title":"A device based on the Shack-Hartmann wave front sensor for testing wide aperture optics","authors":"A. Nikitin, J. Sheldakova, A. Kudryashov, G. Borsoni, D. Denisov, V. Karasik, A. Sakharov","doi":"10.1117/12.2219282","DOIUrl":"https://doi.org/10.1117/12.2219282","url":null,"abstract":"In this paper we consider two approaches widely used in testing of wide aperture optics: Fizeau interferometer and Shack-Hartmann wavefront sensor. Fizeau interferometer that is common instrument in optical testing can be transformed to a device using Shack-Hartmann wavefront sensor, the alternative technique to check wide aperture optical components. We call this device Hartmannometer, and compare its features to those of Fizeau interferometer.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123375621","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. Taudt, T. Baselt, B. Nelsen, H. Assmann, A. Greiner, Edmund Koch, Peter Hartmann
This work introduces a modified low-coherence interferometry approach for nanometer surface-prolometry. The key component of the interferometer is an element with known dispersion which defines the measurement range as well as the resolution. This dispersive element delivers a controlled phase variation which can be detected in the spectral domain and used to reconstruct height differences on a sample. In the chosen setup, both axial resolution and measurement range are tunable by the choice of the dispersive element. The basic working principle was demonstrated by a laboratory setup equipped with a supercontinuum light source ( Δλ= 400-1700 nm). Initial experiments were carried out to characterize steps of 101 nm on a silicon height standard. The results showed that the system delivers an accuracy of about 11.8 nm. These measurements also served as a calibration for the second set of measurements. The second experiment consisted of the measurement of the bevel of a silicon wafer. The modified low-coherence interferometer could be utilized to reproduce the slope on the edge within the previously estimated accuracy. The main advantage of the proposed measurement approach is the possibility to collect data without the need for mechanically moving parts.
{"title":"Measurement of surface topographies in the nm-range for power chip technologies by a modified low-coherence interferometer","authors":"C. Taudt, T. Baselt, B. Nelsen, H. Assmann, A. Greiner, Edmund Koch, Peter Hartmann","doi":"10.1117/12.2212913","DOIUrl":"https://doi.org/10.1117/12.2212913","url":null,"abstract":"This work introduces a modified low-coherence interferometry approach for nanometer surface-prolometry. The key component of the interferometer is an element with known dispersion which defines the measurement range as well as the resolution. This dispersive element delivers a controlled phase variation which can be detected in the spectral domain and used to reconstruct height differences on a sample. In the chosen setup, both axial resolution and measurement range are tunable by the choice of the dispersive element. The basic working principle was demonstrated by a laboratory setup equipped with a supercontinuum light source ( Δλ= 400-1700 nm). Initial experiments were carried out to characterize steps of 101 nm on a silicon height standard. The results showed that the system delivers an accuracy of about 11.8 nm. These measurements also served as a calibration for the second set of measurements. The second experiment consisted of the measurement of the bevel of a silicon wafer. The modified low-coherence interferometer could be utilized to reproduce the slope on the edge within the previously estimated accuracy. The main advantage of the proposed measurement approach is the possibility to collect data without the need for mechanically moving parts.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129916692","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 a novel stabilization method for two frequency combs with a small relative fceo jitter using a selected single optical mode out of a frequency comb. This proposed method is intended to stabilize optical frequencies which generated by two different optical combs with immunity to environmental disturbance, frequency drift and fluctuation with time so as to enhance the measuring performance of dual comb based spectroscopy and distance measurement. A single comb mode is selected out using a composite optical filtering and diode laser injection locking. The selected optical frequency yields a narrow relative linewidth less than 1 Hz and the frequency stability of 1.58×10-17 at 10 s averaging time. By using this, we generated heterodyned beat signal between generated optical frequency and another comb to stabilize relative fceo using phase lock-in control which adjust driving frequency of acousto-optic modulator. As a result of feedback control, the relative jitter is well stabilized down to 1.06×10-15 at 10 s averaging time. This highly stable frequency instability of two combs can perform to enhance the measuring resolution, accuracy and repeatability for dual comb based spectroscopy and distance metrology.
{"title":"Stabilization of two frequency combs with a small relative fceo jitter using diode laser injection locking","authors":"B. Chun, Young‐Jin Kim, Seung-Woo Kim","doi":"10.1117/12.2212838","DOIUrl":"https://doi.org/10.1117/12.2212838","url":null,"abstract":"We report a novel stabilization method for two frequency combs with a small relative fceo jitter using a selected single optical mode out of a frequency comb. This proposed method is intended to stabilize optical frequencies which generated by two different optical combs with immunity to environmental disturbance, frequency drift and fluctuation with time so as to enhance the measuring performance of dual comb based spectroscopy and distance measurement. A single comb mode is selected out using a composite optical filtering and diode laser injection locking. The selected optical frequency yields a narrow relative linewidth less than 1 Hz and the frequency stability of 1.58×10-17 at 10 s averaging time. By using this, we generated heterodyned beat signal between generated optical frequency and another comb to stabilize relative fceo using phase lock-in control which adjust driving frequency of acousto-optic modulator. As a result of feedback control, the relative jitter is well stabilized down to 1.06×10-15 at 10 s averaging time. This highly stable frequency instability of two combs can perform to enhance the measuring resolution, accuracy and repeatability for dual comb based spectroscopy and distance metrology.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115308264","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 introduces a novel imaging spectrometer subsystem concept, the Smart Slit Assembly (SSA), that improves instrument performances and enables new features for future Earth Observation. Derived from CarbonSat (ESA study) requirements, a concept of an SSA based on MEMS micro-shutters/mirrors and associated instrument design aspects are presented. The SSA replaces the classical grating spectrometer slit aperture in the focal plane of the telescope with three core elements, namely an input multimode waveguide array followed by a spatial light modulator (SLM) and an output multimode waveguide array which ends at the slit aperture viewed by the spectrometer. The SLM’s in-and-outputs being coupled to waveguide arrays leads to an enhanced SLM with light de-coherence, polarization scrambling and scene/object homogenization capabilities. The additional advantage of this subsystem’s arrangement is that waveguide level homogeneous spatial light modulation can be achieved with spatially in-homogeneous coupling from in to output multimode waveguides, allowing new, simpler and less costly designs for the SLM part of the SSA. The SSA is particularly useful for instance to reduce stray light by scene/object selection or modulation (e.g. de-clouding, intensity equalization), relax on the required dynamic range of the detectors, increase spectral stability by waveguide level intensity homogenization/scrambling, continuous in-flight monitoring of the co-registration between two or several spectrometer channels and inflight monitoring of stray light.
{"title":"Smart slit assembly for high-resolution spectrometers in space","authors":"B. Guldimann, K. Minoglou","doi":"10.1117/12.2209336","DOIUrl":"https://doi.org/10.1117/12.2209336","url":null,"abstract":"This paper introduces a novel imaging spectrometer subsystem concept, the Smart Slit Assembly (SSA), that improves instrument performances and enables new features for future Earth Observation. Derived from CarbonSat (ESA study) requirements, a concept of an SSA based on MEMS micro-shutters/mirrors and associated instrument design aspects are presented. The SSA replaces the classical grating spectrometer slit aperture in the focal plane of the telescope with three core elements, namely an input multimode waveguide array followed by a spatial light modulator (SLM) and an output multimode waveguide array which ends at the slit aperture viewed by the spectrometer. The SLM’s in-and-outputs being coupled to waveguide arrays leads to an enhanced SLM with light de-coherence, polarization scrambling and scene/object homogenization capabilities. The additional advantage of this subsystem’s arrangement is that waveguide level homogeneous spatial light modulation can be achieved with spatially in-homogeneous coupling from in to output multimode waveguides, allowing new, simpler and less costly designs for the SLM part of the SSA. The SSA is particularly useful for instance to reduce stray light by scene/object selection or modulation (e.g. de-clouding, intensity equalization), relax on the required dynamic range of the detectors, increase spectral stability by waveguide level intensity homogenization/scrambling, continuous in-flight monitoring of the co-registration between two or several spectrometer channels and inflight monitoring of stray light.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133840237","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}
In this work, we present a simple, assembled from readily available components, low cost, imaging vibrometer based on a Twyman-Green interferometer with digital interferogram acquisition, allowing to map displacement contour levels of a harmonically excited piezoelectric membrane, on the principle of exposure integration. We experimentally demonstrate the capabilities of our setup on imaging the 4th mechanical mode of vibration of a 200 micrometer radius piezoelectric micromachined ultrasonic transducer membrane vibrating at 842 kHz, with an out-of-plane amplitude of 475 nm. Our results allow a direct visualization of the influence of etching trenches onto the vibrating membrane, in excellent agreement with FEM simulations.
{"title":"Low-cost facile interferometer for displacement mapping of harmonically excited MEMS","authors":"M. Ma̧dzik, Jaime Viegas","doi":"10.1117/12.2213822","DOIUrl":"https://doi.org/10.1117/12.2213822","url":null,"abstract":"In this work, we present a simple, assembled from readily available components, low cost, imaging vibrometer based on a Twyman-Green interferometer with digital interferogram acquisition, allowing to map displacement contour levels of a harmonically excited piezoelectric membrane, on the principle of exposure integration. We experimentally demonstrate the capabilities of our setup on imaging the 4th mechanical mode of vibration of a 200 micrometer radius piezoelectric micromachined ultrasonic transducer membrane vibrating at 842 kHz, with an out-of-plane amplitude of 475 nm. Our results allow a direct visualization of the influence of etching trenches onto the vibrating membrane, in excellent agreement with FEM simulations.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133655814","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}
S. Padma, Sharath Umesh, Shweta Pant, T. Srinivas, S. Asokan
Goniometer has found extensive usage in diverse applications, primary being medical field in which it is employed for obtaining the range of motion of joints during physical therapy. It is imperative to have a dynamic system to measure the range of motion which will aid for a progressive therapeutic treatment. Hence in the present study, a novel goniometer for real time dynamic angle measurement between two surfaces with the aid of a Fiber Bragg Grating sensor is proposed. The angular rotation between the two surfaces will be identified by the two arms of the Fiber Bragg Grating Goniometer (FBGG), which is translated to the rotation of the shaft which holds these arms together. A cantilever beam is fixed onto the base plate whose free end is connected to the rotating shaft. The rotating shaft will actuate a mechanism which will pull the free end of the cantilever resulting in strain variation over the cantilever beam. The strain variation on the cantilever beam is measured by the Fiber Bragg Grating sensor bonded over it. Further, the proposed FBGG facilitates tunable sensitivity by the discs of varying diameters on the rotating shaft. Tunable sensitivity of the FBGG is realised by the movement of these discs by varying circumferential arc lengths for the same angular movement, which will actuate the pull on the cantilever beam. As per the requirement of the application in terms of resolution and range of angular measurement, individual mode of sensitivity may be selected.
{"title":"Fiber Bragg grating based tunable sensitivity goniometer","authors":"S. Padma, Sharath Umesh, Shweta Pant, T. Srinivas, S. Asokan","doi":"10.1117/12.2212400","DOIUrl":"https://doi.org/10.1117/12.2212400","url":null,"abstract":"Goniometer has found extensive usage in diverse applications, primary being medical field in which it is employed for obtaining the range of motion of joints during physical therapy. It is imperative to have a dynamic system to measure the range of motion which will aid for a progressive therapeutic treatment. Hence in the present study, a novel goniometer for real time dynamic angle measurement between two surfaces with the aid of a Fiber Bragg Grating sensor is proposed. The angular rotation between the two surfaces will be identified by the two arms of the Fiber Bragg Grating Goniometer (FBGG), which is translated to the rotation of the shaft which holds these arms together. A cantilever beam is fixed onto the base plate whose free end is connected to the rotating shaft. The rotating shaft will actuate a mechanism which will pull the free end of the cantilever resulting in strain variation over the cantilever beam. The strain variation on the cantilever beam is measured by the Fiber Bragg Grating sensor bonded over it. Further, the proposed FBGG facilitates tunable sensitivity by the discs of varying diameters on the rotating shaft. Tunable sensitivity of the FBGG is realised by the movement of these discs by varying circumferential arc lengths for the same angular movement, which will actuate the pull on the cantilever beam. As per the requirement of the application in terms of resolution and range of angular measurement, individual mode of sensitivity may be selected.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128265802","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}
Brian Jasenak, Rachel Willsey, A. Willsey, Jamie Forish
Ultraviolet light-emitting diode (UV LED) adoption is accelerating; they are being used in new applications such as UV curing, germicidal irradiation, nondestructive testing, and forensic analysis. In many of these applications, it is critically important to produce a uniform light distribution and consistent surface irradiance. Flat panes of fused quartz, silica, or glass are commonly used to cover and protect multi-UV LED arrays. However, they don’t offer the advantages of an optical lens design. An investigation was conducted to determine the effect of a secondary glass optic on the uniformity of the light distribution and irradiance. Glass optics capable of transmitting UV-A, UV-B, and UV-C wavelengths can improve light distribution and intensity. In this study, a UV transmitting glass formulation and secondary linear optic were designed and manufactured to demonstrate their effects on achievable irradiance intensity and uniformity. Prismatic patterning on the light source surface of the lens was used to minimize reflection losses on the incident surface of the glass. Fresnel optics were molded into the opposite side of the UV transmitting glass to control the refraction of the light and to gain the desired light intensity distribution from two multi-UV LED arrays. A 20% increase in relative irradiance was observed while maintaining the same coverage area. This work discusses the optical design and the resulting benefits of controlled light output on UV LED systems, which include reduced driving current, decreased thermal deterioration, improved energy efficiency, and longer LED lifetime.
{"title":"Investigation of light output uniformity and performance using a UV transmitting glass optic for a multi-UV LED array","authors":"Brian Jasenak, Rachel Willsey, A. Willsey, Jamie Forish","doi":"10.1117/12.2209714","DOIUrl":"https://doi.org/10.1117/12.2209714","url":null,"abstract":"Ultraviolet light-emitting diode (UV LED) adoption is accelerating; they are being used in new applications such as UV curing, germicidal irradiation, nondestructive testing, and forensic analysis. In many of these applications, it is critically important to produce a uniform light distribution and consistent surface irradiance. Flat panes of fused quartz, silica, or glass are commonly used to cover and protect multi-UV LED arrays. However, they don’t offer the advantages of an optical lens design. An investigation was conducted to determine the effect of a secondary glass optic on the uniformity of the light distribution and irradiance. Glass optics capable of transmitting UV-A, UV-B, and UV-C wavelengths can improve light distribution and intensity. In this study, a UV transmitting glass formulation and secondary linear optic were designed and manufactured to demonstrate their effects on achievable irradiance intensity and uniformity. Prismatic patterning on the light source surface of the lens was used to minimize reflection losses on the incident surface of the glass. Fresnel optics were molded into the opposite side of the UV transmitting glass to control the refraction of the light and to gain the desired light intensity distribution from two multi-UV LED arrays. A 20% increase in relative irradiance was observed while maintaining the same coverage area. This work discusses the optical design and the resulting benefits of controlled light output on UV LED systems, which include reduced driving current, decreased thermal deterioration, improved energy efficiency, and longer LED lifetime.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"9768 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129514513","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}
Try to take advantages of the high-resolution CCD/CMOS developed over the years for real-time three-dimensional deformation/geometry metrology system development, Fourier transform (FT) based algorithms have been integrated to convert interference fringes to wrapped phase maps and then to unwrapped phase maps. All of which led to easy implementation of the algorithms developed over the years to achieve extremely efficient FT computation. Sparse Fast Fourier Transform (SFFT) that only calculating the non-zero coefficient in frequency domain, includes calculations of imaginary part and log, was implemented to further accelerate the computation rate for the above-mentioned FT based operations. Coupling the SFFT accelerated phase map computation approach with Michelson interferometer and Electronic Speckle Pattern Interferometry (ESPI) for near real-time three-dimensional deformation measurement led to the newly developed system. The directions of object deformation are revealed by performing FT to the interference fringes obtained with pre-introduced spatial carrier frequency, which provides a way to retrieve the phase maps by using a single rather than several intensity maps. With only one image frame needed, the interference fringes caused by the deformation could be recorded for off-line phase maps computation if the computation efforts are longer than the recording frame rate. To apply the SFFT algorithm on phase retrieval, a conceptual framework was presented. The benefit of using SFFT as compared to FT was also demonstrated.
{"title":"SFFT based phase demodulation for faster interference fringes analysis","authors":"Chen-Yu Lee, Kuan-Yu Hsu, Chih-Kung Lee","doi":"10.1117/12.2211716","DOIUrl":"https://doi.org/10.1117/12.2211716","url":null,"abstract":"Try to take advantages of the high-resolution CCD/CMOS developed over the years for real-time three-dimensional deformation/geometry metrology system development, Fourier transform (FT) based algorithms have been integrated to convert interference fringes to wrapped phase maps and then to unwrapped phase maps. All of which led to easy implementation of the algorithms developed over the years to achieve extremely efficient FT computation. Sparse Fast Fourier Transform (SFFT) that only calculating the non-zero coefficient in frequency domain, includes calculations of imaginary part and log, was implemented to further accelerate the computation rate for the above-mentioned FT based operations. Coupling the SFFT accelerated phase map computation approach with Michelson interferometer and Electronic Speckle Pattern Interferometry (ESPI) for near real-time three-dimensional deformation measurement led to the newly developed system. The directions of object deformation are revealed by performing FT to the interference fringes obtained with pre-introduced spatial carrier frequency, which provides a way to retrieve the phase maps by using a single rather than several intensity maps. With only one image frame needed, the interference fringes caused by the deformation could be recorded for off-line phase maps computation if the computation efforts are longer than the recording frame rate. To apply the SFFT algorithm on phase retrieval, a conceptual framework was presented. The benefit of using SFFT as compared to FT was also demonstrated.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133183661","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}
Advancement of distributed piezo-electret sensors and actuators facilitates various smart systems development, which include paper speakers, opto-piezo/electret bio-chips, etc. The array-based loudspeaker system possess several advantages over conventional coil speakers, such as light-weightness, flexibility, low power consumption, directivity, etc. With the understanding that the performance of the large-area piezo-electret loudspeakers or even the microfluidic biochip transport behavior could be tailored by changing their dynamic behaviors, a full-field real-time high-resolution non-contact metrology system was developed. In this paper, influence of the resonance modes and the transient vibrations of an arraybased loudspeaker system on the acoustic effect were measured by using a real-time projection moiré metrology system and microphones. To make the paper speaker even more versatile, we combine the photosensitive material TiOPc into the original electret loudspeaker. The vibration of this newly developed opto-electret loudspeaker could be manipulated by illuminating different light-intensity patterns. Trying to facilitate the tailoring process of the opto-electret loudspeaker, projection moiré was adopted to measure its vibration. By recording the projected fringes which are modulated by the contours of the testing sample, the phase unwrapping algorithm can give us a continuous phase distribution which is proportional to the object height variations. With the aid of the projection moiré metrology system, the vibrations associated with each distinctive light pattern could be characterized. Therefore, we expect that the overall acoustic performance could be improved by finding the suitable illuminating patterns. In this manuscript, the system performance of the projection moiré and the optoelectret paper speakers were cross-examined and verified by the experimental results obtained.
{"title":"Characterizing opto-electret based paper speakers by using a real-time projection Moiré metrology system","authors":"Ya-Ling Chang, Kuan-Yu Hsu, Chih-Kung Lee","doi":"10.1117/12.2212010","DOIUrl":"https://doi.org/10.1117/12.2212010","url":null,"abstract":"Advancement of distributed piezo-electret sensors and actuators facilitates various smart systems development, which include paper speakers, opto-piezo/electret bio-chips, etc. The array-based loudspeaker system possess several advantages over conventional coil speakers, such as light-weightness, flexibility, low power consumption, directivity, etc. With the understanding that the performance of the large-area piezo-electret loudspeakers or even the microfluidic biochip transport behavior could be tailored by changing their dynamic behaviors, a full-field real-time high-resolution non-contact metrology system was developed. In this paper, influence of the resonance modes and the transient vibrations of an arraybased loudspeaker system on the acoustic effect were measured by using a real-time projection moiré metrology system and microphones. To make the paper speaker even more versatile, we combine the photosensitive material TiOPc into the original electret loudspeaker. The vibration of this newly developed opto-electret loudspeaker could be manipulated by illuminating different light-intensity patterns. Trying to facilitate the tailoring process of the opto-electret loudspeaker, projection moiré was adopted to measure its vibration. By recording the projected fringes which are modulated by the contours of the testing sample, the phase unwrapping algorithm can give us a continuous phase distribution which is proportional to the object height variations. With the aid of the projection moiré metrology system, the vibrations associated with each distinctive light pattern could be characterized. Therefore, we expect that the overall acoustic performance could be improved by finding the suitable illuminating patterns. In this manuscript, the system performance of the projection moiré and the optoelectret paper speakers were cross-examined and verified by the experimental results obtained.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"4 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134570235","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 propose a new hybrid 3D light detection and ranging (LIDAR) system, which measures a scene with 1280 x 600 pixels at a refresh rate of 60fps. The emitted pulses of each pixel are modulated by direct sequence optical code division multiple access (DS-OCDMA) techniques. The modulated pulses include a unique device identification number, the pixel position in the line, and a checksum. The LIDAR emits the modulated pulses periodically without waiting to receive returning light at the detector. When all the pixels are completely through the process, the travel time, amplitude, width, and speed are used by the pixel-by-pixel scanning LIDAR imager to generate point cloud data as the measured results. We programmed the entire hybrid 3D LIDAR operation in a simulator to observe the functionality accomplished by our proposed model.
我们提出了一种新的混合3D光探测和测距(LIDAR)系统，该系统以60fps的刷新率测量1280 x 600像素的场景。每个像素的发射脉冲通过直接序列光码分多址(DS-OCDMA)技术进行调制。所述调制脉冲包括唯一的设备标识号、在所述线中的像素位置和校验和。激光雷达周期性地发射调制脉冲，而无需等待探测器接收返回的光。当所有像素完全通过该过程后，逐像素扫描LIDAR成像仪利用其行程时间、幅度、宽度和速度生成点云数据作为测量结果。我们在模拟器中对整个混合3D激光雷达操作进行了编程，以观察我们提出的模型所实现的功能。
{"title":"A hybrid 3D LIDAR imager based on pixel-by-pixel scanning and DS-OCDMA","authors":"Gunzung Kim, Jeongsook Eom, Yongwan Park","doi":"10.1117/12.2208274","DOIUrl":"https://doi.org/10.1117/12.2208274","url":null,"abstract":"We propose a new hybrid 3D light detection and ranging (LIDAR) system, which measures a scene with 1280 x 600 pixels at a refresh rate of 60fps. The emitted pulses of each pixel are modulated by direct sequence optical code division multiple access (DS-OCDMA) techniques. The modulated pulses include a unique device identification number, the pixel position in the line, and a checksum. The LIDAR emits the modulated pulses periodically without waiting to receive returning light at the detector. When all the pixels are completely through the process, the travel time, amplitude, width, and speed are used by the pixel-by-pixel scanning LIDAR imager to generate point cloud data as the measured results. We programmed the entire hybrid 3D LIDAR operation in a simulator to observe the functionality accomplished by our proposed model.","PeriodicalId":122702,"journal":{"name":"SPIE OPTO","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121258661","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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