Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138846
M. Pizzocaro, F. Bregolin, G. Milani, B. Rauf, P. Thoumany, G. Costanzo, F. Levi, D. Calonico
We present an optical lattice clock based on ytterbium 171Yb atoms developed in the laboratories of INRIM. In the experiment, we cool and trap ytterbium atoms in a two stage magneto-optical trap (MOT) (at 399nm and 556nm for the first and second stage, respectively). Atoms are then transferred in a horizontal, one-dimensional optical lattice at the magic wavelength (759 nm). Here the clock transition at 578nm is probed by a laser stabilized on an ultra-stable cavity. We describe the generation of all the laser sources, the physic package and the operation of the clock. Lasers at 399 nm, 556nm and 578nm are obtained, with different techniques, using non-linear crystals starting from infrared sources. The clock laser is stabilized using a high finesse notched ULE cavity. The lattice is made with a titanium-sapphire laser. The aluminum vacuum chamber is designed for wide optical access and its temperature is measured by 8 thermistors for blackbody shift evaluation. Our system allows for fast loading of the lattice with 1 × 104 atoms trapped in the lattice in 250 ms. We obtained preliminary spectroscopy results and we locked the clock laser to the atomic line. Future perspectives are discussed.
{"title":"Ytterbium optical lattice clock at INRIM","authors":"M. Pizzocaro, F. Bregolin, G. Milani, B. Rauf, P. Thoumany, G. Costanzo, F. Levi, D. Calonico","doi":"10.1109/FCS.2015.7138846","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138846","url":null,"abstract":"We present an optical lattice clock based on ytterbium 171Yb atoms developed in the laboratories of INRIM. In the experiment, we cool and trap ytterbium atoms in a two stage magneto-optical trap (MOT) (at 399nm and 556nm for the first and second stage, respectively). Atoms are then transferred in a horizontal, one-dimensional optical lattice at the magic wavelength (759 nm). Here the clock transition at 578nm is probed by a laser stabilized on an ultra-stable cavity. We describe the generation of all the laser sources, the physic package and the operation of the clock. Lasers at 399 nm, 556nm and 578nm are obtained, with different techniques, using non-linear crystals starting from infrared sources. The clock laser is stabilized using a high finesse notched ULE cavity. The lattice is made with a titanium-sapphire laser. The aluminum vacuum chamber is designed for wide optical access and its temperature is measured by 8 thermistors for blackbody shift evaluation. Our system allows for fast loading of the lattice with 1 × 104 atoms trapped in the lattice in 250 ms. We obtained preliminary spectroscopy results and we locked the clock laser to the atomic line. Future perspectives are discussed.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"11 17 1","pages":"300-303"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78404142","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138890
F. Sun, Xian-he Huang
Ramsey cavity is one of core components that compose the Cs beam tube in the Cs atomic beam clocks. In this work, the contribution from the waveguide bend on the field distribution of the cavity is carefully investigated by using combination method of Maxwell equations and Finite element simulation. We find that there exists TM11 mode inside cavity in addition to standing wave TE10p mode. Meanwhile, we also find that the cavity resonance frequency is closely related to the bend radius. These results demonstrate a better description of the microwave properties than previous work where the Ramsey cavity was usually studied as an ideal rectangular microwave cavity.
{"title":"The effect of bend on the Ramsey cavity","authors":"F. Sun, Xian-he Huang","doi":"10.1109/FCS.2015.7138890","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138890","url":null,"abstract":"Ramsey cavity is one of core components that compose the Cs beam tube in the Cs atomic beam clocks. In this work, the contribution from the waveguide bend on the field distribution of the cavity is carefully investigated by using combination method of Maxwell equations and Finite element simulation. We find that there exists TM11 mode inside cavity in addition to standing wave TE10p mode. Meanwhile, we also find that the cavity resonance frequency is closely related to the bend radius. These results demonstrate a better description of the microwave properties than previous work where the Ramsey cavity was usually studied as an ideal rectangular microwave cavity.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"39 1","pages":"487-491"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80043068","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138918
Z. Xu, Kaikai Huang, Xuanhui Lu
We have implemented a long-term frequency stabilization system for external cavity diode laser (ECDL) based on mode boundary detection method. In this system, the saturated absorption spectroscopy was used. The current and the grating of the ECDL were controlled by a computer-based feedback control system. By checking any mode boundaries in the spectrum, the control system determined how to adjust current to avoid mode hopping. This procedure was executed periodically to ensure the long-term stabilization of ECDL in the absence of mode hops. This laser diode system without antireflection-coating had over operated in the condition of long-term mode hopping free stabilization for almost 400 hours. Last year, we have added template matching technics to the system. The ECDL stabilization time has been extended to almost 1200 hours without any manual intervention further. This is a significant improvement of ECDL frequency stabilization system. This technique is very useful in some applications such as laser atomic cooling and atom fountain etc.
{"title":"External cavity diode laser with long-term frequency stabilization based on mode boundary detection","authors":"Z. Xu, Kaikai Huang, Xuanhui Lu","doi":"10.1109/FCS.2015.7138918","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138918","url":null,"abstract":"We have implemented a long-term frequency stabilization system for external cavity diode laser (ECDL) based on mode boundary detection method. In this system, the saturated absorption spectroscopy was used. The current and the grating of the ECDL were controlled by a computer-based feedback control system. By checking any mode boundaries in the spectrum, the control system determined how to adjust current to avoid mode hopping. This procedure was executed periodically to ensure the long-term stabilization of ECDL in the absence of mode hops. This laser diode system without antireflection-coating had over operated in the condition of long-term mode hopping free stabilization for almost 400 hours. Last year, we have added template matching technics to the system. The ECDL stabilization time has been extended to almost 1200 hours without any manual intervention further. This is a significant improvement of ECDL frequency stabilization system. This technique is very useful in some applications such as laser atomic cooling and atom fountain etc.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"11 1","pages":"606-610"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85244250","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138862
A. Bauch, E. Staliuniene, G. Gomah
This paper deals with the local realization of Coordinated Universal Time UTC by PTB, named UTC(PTB), and PTB's free atomic time scale TA(PTB). Since February 2010 UTC(PTB) has been derived from an active hydrogen maser steered in frequency by PTB's primary fountain clocks. Since then and up to early 2015 the time difference UTC - UTC(PTB) was always less than 9 ns. From early on it was foreseen that the steering of UTC(PTB) could also be derived from the ensemble of caesium beam clocks operated in PTB. When doing so in practice, it appeared that the algorithm of combining the inputs of individual clocks was not perfectly chosen. The properties of the time scales as generated up to now as well as the new strategy for a time scale reflecting better PTB's ensemble of thermal beam caesium clocks is presented in this paper.
本文讨论了协调世界时UTC(Coordinated Universal Time UTC,简称UTC, PTB)的局部实现,以及PTB的自由原子时标TA(PTB)。自2010年2月以来,协调世界时(PTB)已经由PTB主喷泉时钟控制频率的主动氢脉泽派生。从那时起到2015年初,UTC - UTC(PTB)的时差一直小于9秒。从早期就预见到UTC(PTB)的导向也可以从在PTB中运行的铯束钟的集合中得到。在实际操作中,结合各个时钟输入的算法似乎没有被完美地选择。本文介绍了迄今为止产生的时间尺度的性质,以及更好地反映PTB热束铯钟系综的时间尺度的新策略。
{"title":"A status report on time scale generation in PTB","authors":"A. Bauch, E. Staliuniene, G. Gomah","doi":"10.1109/FCS.2015.7138862","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138862","url":null,"abstract":"This paper deals with the local realization of Coordinated Universal Time UTC by PTB, named UTC(PTB), and PTB's free atomic time scale TA(PTB). Since February 2010 UTC(PTB) has been derived from an active hydrogen maser steered in frequency by PTB's primary fountain clocks. Since then and up to early 2015 the time difference UTC - UTC(PTB) was always less than 9 ns. From early on it was foreseen that the steering of UTC(PTB) could also be derived from the ensemble of caesium beam clocks operated in PTB. When doing so in practice, it appeared that the algorithm of combining the inputs of individual clocks was not perfectly chosen. The properties of the time scales as generated up to now as well as the new strategy for a time scale reflecting better PTB's ensemble of thermal beam caesium clocks is presented in this paper.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"67 1","pages":"379-383"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81108531","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138836
M. Abgrall, S. Bize, B. Chupin, J. Guéna, P. Laurent, P. Rosenbusch, P. Uhrich, G. Rovera
This paper presents the current results obtained with the new version of the French timescale UTC(OP) in operation since more than two years now. The time scale is based on an hydrogen maser steered by one of the SYRTE atomic fountains. Thanks to this technique, UTC(OP) is one of the best real time realization of UTC. A statistical analysis of different UTC - UTC(k) comparisons is presented.
{"title":"Stability analysis of the French timescale UTC(OP)","authors":"M. Abgrall, S. Bize, B. Chupin, J. Guéna, P. Laurent, P. Rosenbusch, P. Uhrich, G. Rovera","doi":"10.1109/FCS.2015.7138836","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138836","url":null,"abstract":"This paper presents the current results obtained with the new version of the French timescale UTC(OP) in operation since more than two years now. The time scale is based on an hydrogen maser steered by one of the SYRTE atomic fountains. Thanks to this technique, UTC(OP) is one of the best real time realization of UTC. A statistical analysis of different UTC - UTC(k) comparisons is presented.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"115 1","pages":"257-259"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78584886","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138847
M. Zawada, M. Bober, P. Morzyński, A. Cygan, D. Lisak, P. Masłowski, M. Prymaczek, P. Wcisło, P. Ablewski, M. Piwiński, S. Wójtewicz, K. Bielska, D. Bartoszek-Bober, R. Ciuryło, J. Zachorowski, M. Piotrowski, W. Gawlik, F. Ozimek, C. Radzewicz
We report a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. This allows verification of relative stability of both optical standards. The absolute frequency of the clocks can be roughly verified by the use of an optical frequency comb with the GPS-disciplined Rb frequency standard or, more accurately, by a long distance stabilized fiber optic link with the UTC(AOS) and UTC(PL) via the OPTIME network.
{"title":"Two independent strontium optical lattice clocks for practical realization of the meter and secondary representation of the second","authors":"M. Zawada, M. Bober, P. Morzyński, A. Cygan, D. Lisak, P. Masłowski, M. Prymaczek, P. Wcisło, P. Ablewski, M. Piwiński, S. Wójtewicz, K. Bielska, D. Bartoszek-Bober, R. Ciuryło, J. Zachorowski, M. Piotrowski, W. Gawlik, F. Ozimek, C. Radzewicz","doi":"10.1109/FCS.2015.7138847","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138847","url":null,"abstract":"We report a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. This allows verification of relative stability of both optical standards. The absolute frequency of the clocks can be roughly verified by the use of an optical frequency comb with the GPS-disciplined Rb frequency standard or, more accurately, by a long distance stabilized fiber optic link with the UTC(AOS) and UTC(PL) via the OPTIME network.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"523 1","pages":"304-306"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78154567","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138852
U. Rohde, A. Poddar, E. Rubiola, M. Silaghi
This paper describes the recent trend of front-end receiver systems for the application in radio monitoring. The receiver implementation is optimized for applications such as hunting and detecting unknown signals, identifying interference, spectrum monitoring and clearance, and signal search over wide frequency ranges, producing signal content and direction finding of identified signals.
{"title":"Front-end receiver: Recent and emerging trend","authors":"U. Rohde, A. Poddar, E. Rubiola, M. Silaghi","doi":"10.1109/FCS.2015.7138852","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138852","url":null,"abstract":"This paper describes the recent trend of front-end receiver systems for the application in radio monitoring. The receiver implementation is optimized for applications such as hunting and detecting unknown signals, identifying interference, spectrum monitoring and clearance, and signal search over wide frequency ranges, producing signal content and direction finding of identified signals.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"15 1","pages":"326-331"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72891838","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138783
Jianfeng Chen, Y. Yong, R. Kubena, D. Kirby, D. Chang
The nonlinear effects of initial stress/strain of the quartz plate resonator on its acceleration sensitivity was studied. Finite element models were developed using a theory of small deformations superposed on finite initial deformations in a Lagrangian formulation. AT- and SC-cut quartz circular plate resonators were studied. The plates were respectively subjected to diametrical compression force and bending force. The initial strains due to the application of diametrical force represented initial strains due to in-plane acceleration, while the initial strains due to bending force represented initial strains due to out-of-plane acceleration. Our model results using nonlinear initial strains showed good agreement with measured data by Ballato, Mingins, and Fletcher and Douglas. The model results using linear initial strains compared well only with the measured data for plates subjected to diametrical force but not for plates subjected to bending forces. Hence our model results showed that for accurate prediction of out-of-plane acceleration sensitivity the nonlinear initial strains must be used. The linear initial stress/strain cannot fully capture rotation and bending effects. The acceleration sensitivity model using linear initial strains could only be employed for in-plane acceleration, or for very low g out-of-plane acceleration. The SC-cut crystals showed better linearity of frequency change with respect to applied bending forces than the AT-cut crystals. The principle of superposition for out-of-plane acceleration sensitivity in AT-cut crystals is in general not valid, especially in cases of high g accelerations.
{"title":"Nonlinear acceleration sensitivity of quartz resonators","authors":"Jianfeng Chen, Y. Yong, R. Kubena, D. Kirby, D. Chang","doi":"10.1109/FCS.2015.7138783","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138783","url":null,"abstract":"The nonlinear effects of initial stress/strain of the quartz plate resonator on its acceleration sensitivity was studied. Finite element models were developed using a theory of small deformations superposed on finite initial deformations in a Lagrangian formulation. AT- and SC-cut quartz circular plate resonators were studied. The plates were respectively subjected to diametrical compression force and bending force. The initial strains due to the application of diametrical force represented initial strains due to in-plane acceleration, while the initial strains due to bending force represented initial strains due to out-of-plane acceleration. Our model results using nonlinear initial strains showed good agreement with measured data by Ballato, Mingins, and Fletcher and Douglas. The model results using linear initial strains compared well only with the measured data for plates subjected to diametrical force but not for plates subjected to bending forces. Hence our model results showed that for accurate prediction of out-of-plane acceleration sensitivity the nonlinear initial strains must be used. The linear initial stress/strain cannot fully capture rotation and bending effects. The acceleration sensitivity model using linear initial strains could only be employed for in-plane acceleration, or for very low g out-of-plane acceleration. The SC-cut crystals showed better linearity of frequency change with respect to applied bending forces than the AT-cut crystals. The principle of superposition for out-of-plane acceleration sensitivity in AT-cut crystals is in general not valid, especially in cases of high g accelerations.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"69 1","pages":"11-16"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79990905","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138883
Wang Zhong, Zhao Jianye, Zhao Xiaona, Liu Li, Zhuang Yuxin, Liao Dawei
We have demonstrated an atomic frequency micrometer based on the coherent population beating phenomenon, which enables us to obtain the beat frequency between the measured signal and the atomic transition frequency. The beat frequency and its fluctuations are detected and accurately measured through digital signal processing, which is capable of up to mHz or higher frequency resolutions (for GHz signal). The frequency discrimination via our method is comparable to that of the Ramsey fringes method, and the working range is no longer limited by the width of line shape. This enables us to achieve an atomic clock by actively compensating the frequency shift, which eliminates the need for a phase locking loop, and broadens the working range with increasing reliability. This novel scheme could be extended to the optical frequency region, implying possible future applications in optical atomic clocks, optical frequency comb, atomic spectroscopy and other related researches.
{"title":"An atomic frequency micrometer based on the coherent population beating phenomenon","authors":"Wang Zhong, Zhao Jianye, Zhao Xiaona, Liu Li, Zhuang Yuxin, Liao Dawei","doi":"10.1109/FCS.2015.7138883","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138883","url":null,"abstract":"We have demonstrated an atomic frequency micrometer based on the coherent population beating phenomenon, which enables us to obtain the beat frequency between the measured signal and the atomic transition frequency. The beat frequency and its fluctuations are detected and accurately measured through digital signal processing, which is capable of up to mHz or higher frequency resolutions (for GHz signal). The frequency discrimination via our method is comparable to that of the Ramsey fringes method, and the working range is no longer limited by the width of line shape. This enables us to achieve an atomic clock by actively compensating the frequency shift, which eliminates the need for a phase locking loop, and broadens the working range with increasing reliability. This novel scheme could be extended to the optical frequency region, implying possible future applications in optical atomic clocks, optical frequency comb, atomic spectroscopy and other related researches.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"282 1","pages":"465-470"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76810649","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}
Pub Date : 2015-04-12DOI: 10.1109/FCS.2015.7138870
Gongbin Tang, Tao Han, Akihiko Teshigahara, T. Iwaki, K. Hashimoto
This paper describes drastic enhancement of Ke2 by mass loading in layered SAW device structures such as the ScAlN film/Si substrate. It is shown that this phenomenon is obvious even when an amorphous SiO2 film is deposited on the top surface for temperature compensation. This enhancement is caused by SAW energy confinement to the top surface of the ScAlN layer where the IDT is placed. This Ke2 enhancement is also found when other electrode and/or substrate materials are employed.
{"title":"Enhancement of effective electromechanical coupling factor by mass loading in layered SAW device structures","authors":"Gongbin Tang, Tao Han, Akihiko Teshigahara, T. Iwaki, K. Hashimoto","doi":"10.1109/FCS.2015.7138870","DOIUrl":"https://doi.org/10.1109/FCS.2015.7138870","url":null,"abstract":"This paper describes drastic enhancement of K<sub>e</sub><sup>2</sup> by mass loading in layered SAW device structures such as the ScAlN film/Si substrate. It is shown that this phenomenon is obvious even when an amorphous SiO<sub>2</sub> film is deposited on the top surface for temperature compensation. This enhancement is caused by SAW energy confinement to the top surface of the ScAlN layer where the IDT is placed. This K<sub>e</sub><sup>2</sup> enhancement is also found when other electrode and/or substrate materials are employed.","PeriodicalId":57667,"journal":{"name":"时间频率公报","volume":"271 1","pages":"416-419"},"PeriodicalIF":0.0,"publicationDate":"2015-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77175338","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}