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Mapping of the surface profile of an asymmetric dielectric microcavity and identification of shape-sensitive internal modes : 비대칭 유전체 미소 공진기의 경계형태 측정 및 형태에 민감한 내부 모드 분석
DC Field | Value | Language |
---|---|---|
dc.contributor.advisor | 안경원 | - |
dc.contributor.author | 문송기 | - |
dc.date.accessioned | 2017-07-14T00:58:03Z | - |
dc.date.available | 2017-07-14T00:58:03Z | - |
dc.date.issued | 2014-02 | - |
dc.identifier.other | 000000017754 | - |
dc.identifier.uri | https://hdl.handle.net/10371/121523 | - |
dc.description | 학위논문 (박사)-- 서울대학교 대학원 : 물리·천문학부(물리학전공), 2014. 2. 안경원. | - |
dc.description.abstract | In this thesis, I first present a non-destructive and non-contact highresolution
optical technique for profiling soft or fluidic boundary of an opaque object. This technique utilizes the fact that the angle width, the angular separation between two adjacent intensity minima in the forward shadow diffraction, is inversely proportional to the projected width of the object in the same direction. An analytic formula for reconstructing the boundary shape is obtained for an object with two-fold symmetry in terms of the angle widths measured for various rotational angles of the object. The typical error in determining the object shape parameter is less than 0.2%, which corresponds to 20 nm of radial accuracy when applied to an object with a mean radius of 10 μm. I then apply the profiling technique to asymmetric liquid micro jet cavity and determine its surface profile in the accuracy enough to analyze the experimental results with theoretical concepts based on the one-to-one comparison between the experiments and with the numerical simulations. I found that the most dominant oscillation mode of our jet is the combination of quadrupolar and octapolar waves. The amplitudes of these two components are related by a certain quadratic relation, η2≃Bη1 2 ( η1 and η2 are amplitudes of quadrupolar and octapolar oscillation, respectively). The coefficient B is obtained as 0.42±0.08. I also survey the surface vibration of a microjet analytically by modifying Niels Bohrs non-linear hydrodynamical i treatment of the same problem, and find out that the expected value of B from this theory is nearly 0.41. The measured result and the theoretical prediction agree experimental error. With this information, fundamental intra quasi-mode positions can be predicted by simulation within experimental error. Moreover, I also confirm that numerical simulations show good agreement with spectroscopic experimental results for non-trivial features of quasi-mode dynamics such as avoided crossing gaps. | - |
dc.description.tableofcontents | 1 Introduction 1
2 Surface oscillation and cavity boundary 5 2.1 Surface oscillation of a liquid column . . . . . . . . . . . . . 5 2.2 Deformation-tunable liquid microjet cavity . . . . . . . . . . 8 2.3 The linear theory of the surface oscillation of a liquid jet . . 14 2.3.1 The master equations . . . . . . . . . . . . . . . . . . 14 2.3.2 The linear theory : approximated master equations and their solution . . . . . . . . . . . . . . . . . . . . 15 2.3.3 Application of the linear theory on the microjet cavity 16 2.4 Failure of the linear theory : experimental evidences . . . . . 18 2.4.1 Cavity boundary and cavity-modified fluorescence spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.4.2 Results of the comparison . . . . . . . . . . . . . . . 21 2.4.3 Shape sensitivity of high-Q modes : A discussion on effect of a small perturbation in classical dynamics . 23 2.5 Non-linear solution . . . . . . . . . . . . . . . . . . . . . . . 29 2.5.1 Niels Bohrs modification . . . . . . . . . . . . . . . . 29 2.5.2 Separation of the master equations by order of perturbation . . . . . . . . . . . . . . . . . . . . . . . . 32 2.5.3 The first order solution . . . . . . . . . . . . . . . . . 34 2.5.4 The second order solution . . . . . . . . . . . . . . . 35 3 Development of surface mapping technique 41 3.1 A review of preceding studies . . . . . . . . . . . . . . . . . 41 3.2 Forward diffraction pattern by an opaque object . . . . . . . 43 3.3 Derivation of the forward shadow diffraction pattern by an opaque object . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3.3.1 Relation between the angle width function and the projected width . . . . . . . . . . . . . . . . . . . . . 53 3.3.2 Examples . . . . . . . . . . . . . . . . . . . . . . . . 55 3.4 Surface profiling of a two-dimensional object . . . . . . . . . 57 3.4.1 Description of measurement geometry . . . . . . . . . 57 3.4.2 Shape reconstruction algorithm . . . . . . . . . . . . 57 3.4.3 Projected width in the direction of angle width measurement . . . . . . . . . . . . . . . . . . . . . . . . . 60 3.4.4 What happens if the two-fold symmetry is not there? 61 3.4.5 Examples of the shape reconstruction and an accuracy evaluation . . . . . . . . . . . . . . . . . . . . . 63 4 Surface reconstruction of the liquid microjet and identification of internal modes 67 4.1 Realization of the surface mapping method . . . . . . . . . . 67 4.2 Relation between the quadrupolar and octapolar components 70 4.2.1 General remarks on the reconstructed profiles . . . . 70 4.2.2 Measuring B . . . . . . . . . . . . . . . . . . . . . . . 70 4.2.3 Discussion on the result . . . . . . . . . . . . . . . . 73 4.3 Analyzing tools of the spectroscopic experiments . . . . . . . 76 4.3.1 Free spectral range and the locally repeated structure in a CMF spectrum . . . . . . . . . . . . . . . . . . . 76 4.3.2 Grouping of the quasi-modes in the cavity-modified fluorescence spectrum . . . . . . . . . . . . . . . . . . 77 4.3.3 Quasi-mode evolution diagram . . . . . . . . . . . . . 79 4.3.4 The ordering of the quasi-mode groups . . . . . . . . 83 4.4 Identification of the internal high-Q modes . . . . . . . . . . 83 4.4.1 Preparations . . . . . . . . . . . . . . . . . . . . . . . 83 4.4.2 Matching of the quasi-mode evolution diagram . . . . 87 4.4.3 A consideration of the avoided crossing gap and the tolerance of the reconstructed profile . . . . . . . . . 94 5 Conclusion 97 A More comparison of a quadrupolar-deformed resonator with the microjet cavity 99 A.1 A problem of delayed chaotic transition of the microjet cavity compared with QDMs . . . . . . . . . . . . . . . . . . 99 A.2 Quasi-mode evolution diagrams for QDMs and discussions . 100 B On the calibration of the relative size parameter X of experimentally detected resonances 106 C On an expectation of threshold-vanishing effect of a microjet cavity laser near the exceptional point in the parametric space 111 | - |
dc.format | application/pdf | - |
dc.format.extent | 6782873 bytes | - |
dc.format.medium | application/pdf | - |
dc.language.iso | en | - |
dc.publisher | 서울대학교 대학원 | - |
dc.subject | non-destructive measurement | - |
dc.subject | surface oscillation | - |
dc.subject | liquid jet | - |
dc.subject | hydrodynamics | - |
dc.subject | deformed microcavity | - |
dc.subject | whispering gallery mode | - |
dc.subject | quasi-mode interaction | - |
dc.subject | fluorescence spectroscopy | - |
dc.subject | shape-sensitive mode dynamics | - |
dc.subject.ddc | 523 | - |
dc.title | Mapping of the surface profile of an asymmetric dielectric microcavity and identification of shape-sensitive internal modes | - |
dc.title.alternative | 비대칭 유전체 미소 공진기의 경계형태 측정 및 형태에 민감한 내부 모드 분석 | - |
dc.type | Thesis | - |
dc.description.degree | Doctor | - |
dc.citation.pages | xii, 124 | - |
dc.contributor.affiliation | 자연과학대학 물리·천문학부(물리학전공) | - |
dc.date.awarded | 2014-02 | - |
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