Diorico encallado

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Amanda D. Encallado, Fritz Randulf S. Diorico Department of Physics, University of San Carlos Talamban, Cebu City, Philippines 6000 [email protected], [email protected] Advisers: Albert James Licup and Claude Ceniza

Transcript of Diorico encallado

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Amanda D. Encallado, Fritz Randulf S. DioricoDepartment of Physics, University of San CarlosTalamban, Cebu City, Philippines [email protected], [email protected]: Albert James Licup and Claude Ceniza

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PRESENTATION OUTLINE

Introduction

Theory

Methodology

Results

Conclusions

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INTRODUCTION

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Fizeau interferometer

InSAR

INTRODUCTION

Michelson interferometer

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Case 1: Flat Case 1: Flat surfacesurface

Case 2: Flat surface + round Case 2: Flat surface + round peripheryperiphery

Case 3: Convex surface + round Case 3: Convex surface + round peripheryperipheryCase 4: Concave surface + round Case 4: Concave surface + round peripheryperiphery

INTRODUCTION

INTERFEROGRAM CORRESPONDENCE OF LENS SURFACE

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To construct a Fizeau interferometer

To be able to automate the three-dimensional reconstruction of the lens surface.

To obtain a three dimensional perspective of lenses

OBJECTIVES

INTRODUCTION

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THEORY

4 ( , )( , ) airn d x yx y

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1-D Interference

Fourier Transform

Inverse Fourier Transform

Phase Unwrapping

THEORY

*( , ) ( , ) ( , ) ( , )i x y a x y c x y c x y *( , ) ( , ) ( , ) ( , )I u v A u v C u v C u v

( , )1( , ) ( , )

2j x yc x y b x y e

1 Im ( , )( , ) tan

Re ( , )

c x yx y

c x y

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THEORY

Phase Sign Ambiguity Correction

Interferogram Frequency Spectrum Wrapped Phase Distribution

Different possible orientations for filters for the Frequency Spectrum

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Phase Sign Ambiguity Correction

Interferogram Frequency Spectrum Multi-regional filters

Resulting Phase Distributions Phase Masks

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Phase Sign Ambiguity Correction

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Phase Sign Ambiguity Correction

Sign corrected phase distribution

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THEORY

Phase Unwrapping

4

1yx xy i

i

q

0.1 0.2 0.3

-0.1 -0.2 -0.4

-0.2 -0.2 -0.3

0.1 0.2 0.3

-0.1 -0.2 -0.4

-0.2 -0.2 -0.3

0.1 0.2 0.3

-0.1 -0.2 -0.4

-0.2 -0.2 -0.3

0.1 0.2 0.3

-0.1 -0.2 -0.4

-0.2 -0.2 -0.3

0.1 0.2 0.3

-0.1 -0.2 -0.4

-0.2 -0.2 -0.3

1234

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THEORY

Phase Unwrapping

+

-

+

-

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THEORY

Phase Unwrapping

Residue Distribution Branch Cuts

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Phase Unwrapping

THEORY

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Modified version of the Fizeau Interferometer

Beam Expander

Beam Splitter 50-50

Screen

Optical Flat or Reference FlatLens under

observation

Interferogram to be captured by

CCD camera and Analyze using

MATLAB®

Collimated Beam

C

CD

METHODOLOGY

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If Complex

Multi-regional filtering

Fourier Transform

Pre-processed interferogram from LabVIEW

Phase-Unwrapping using Goldstein’s Branch Cut Algorithm

Pizza-slice masks append

View 3-D Lens Surface

Inverse FT

If Non-complex

Select best Phase Derivative Variance

METHODOLOGY

Information Flow Diagram

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Interferogram

RESULTS

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Log magnitude spectrum

RESULTS

( , ) *( , )C u v or C u v

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Multi-regional filters

RESULTS

Filtered frequency domain

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Wrapped

Phase

Distribution

Phase

Derivative

Variance

RESULTS

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Wrapped Phase Distribution of highest quality

Phase residues

Branch cuts

RESULTS

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Wrapped phase distribution

Unwrapped phase

RESULTS

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Unwrapped Phase

Unwrapping Error

1, , ,( 1, ) xx i j i j i jx y

, 1 , ,( , 1) yy i j i j i jx y

x y (mean: 0.008, max: 12.57 radians)

RESULTS

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RESULTS

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Displacement plot

Displacement error(mean: 0.001,

max: 0.649 μm)

RESULTS

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Interferogram

Wrapped Phase Distribution

RESULTS

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Without mean filtering

Mean= 0.011 radians

With mean filteringMean=0.008

radians

RESULTS

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Phase residues

Branch cuts

Unwrapped Phase

RESULTS

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RESULTS

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Displacement plot

Displacement errormean: 0.001, max: 1.343 μm)

RESULTS

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Precision and Accuracy ±1.343 μm (accuracy based on unwrapping error) with mean =

0.001 μm Precision:

4 4precisiond z

2precision m

where m is the number of samples per fringe4 ( , )

( , ) airn d x yx y

0.1584

d m

RESULTS

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2

4 4

Nd z

m

RESULTS

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Conclusions Phase Measurement using the Fourier

transform method Multi-regional filtering for sign ambiguity

correction Goldstein’s branch cut algorithm,

obtained minimum PU error, 0.001 radians.

Displacement error through PU error Displacement resolution > 3-D Reconstruction process, successfully

implemented

0.158 m

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