Download presentation
1
ECE-1466 Modern Optics Course Notes Part 3
Prof. Charles A. DiMarzio Northeastern University Spring 2002 March 02002 Chuck DiMarzio, Northeastern University
2
Chuck DiMarzio, Northeastern University
Diffraction Fresnel-Kirchoff Integral Fraunhofer Approximation Some Common Examples Fourier Optics Generalized Pupil Function Optical Testing Diffraction Gratings Gaussian Beams March 02002 Chuck DiMarzio, Northeastern University
3
Fresnel-Kirchoff Integral (1)
The Basic Equation An Approximation March 02002 Chuck DiMarzio, Northeastern University
4
Fresnel-Kirchoff Integral (2)
March 02002 Chuck DiMarzio, Northeastern University
5
Paraxial Approximation
z March 02002 Chuck DiMarzio, Northeastern University
6
Circular Aperture, Uniform Field
March 02002 Chuck DiMarzio, Northeastern University
7
Square Aperture, Uniform Field
March 02002 Chuck DiMarzio, Northeastern University
8
No Aperture, Gaussian Field
March 02002 Chuck DiMarzio, Northeastern University
9
Chuck DiMarzio, Northeastern University
Fraunhoffer Examples March 02002 Chuck DiMarzio, Northeastern University
10
Single-Mode Optical Fiber
Beam too Large (lost power at edges) Beam too Small (lost power through cladding) March 02002 Chuck DiMarzio, Northeastern University
11
Resolution: Rayleigh Criterion
March 02002 Chuck DiMarzio, Northeastern University
12
Chuck DiMarzio, Northeastern University
Fourier Optics Revisit of the Fresnel-Kirchoff Integral The Fourier Transform Definition of the Spatial Frequencies Relation to Pupils Some Examples Optical Testing Gratings March 02002 Chuck DiMarzio, Northeastern University
13
Fraunhofer Diffraction (1)
March 02002 Chuck DiMarzio, Northeastern University
14
Fraunhofer Diffraction (2)
March 02002 Chuck DiMarzio, Northeastern University
15
Linear Systems Approach to Imaging
x x’ Any Optical System Exit Window Entrance Window Isoplanatic March 02002 Chuck DiMarzio, Northeastern University
16
Chuck DiMarzio, Northeastern University
Terminology h is called the point spread function (PSF) H is called the optical transfer function (OTF) Magnitude is called Modulation Transfer Function (MTF) Phase is Phase Transfer Function (PTF) fx and fy are spatial frequencies Uobject Uimage Uobject Uimage March 02002 Chuck DiMarzio, Northeastern University
17
Concepts of Fourier Optics
Any Isoplanatic Optical System Exit Window Entrance Window Entrance Pupil Exit Pupil Scale x,y and Multiply by OTF Fourier Transform Fourier Transform March 02002 Chuck DiMarzio, Northeastern University
18
Chuck DiMarzio, Northeastern University
Kohler Illumination Illumination Source in a Pupil Plane Incoherent Source Fourier Transform Has Uniform Power Homework Exercise March 02002 Chuck DiMarzio, Northeastern University
19
Some Resolution Charts (1)
Edge Point and Lines Sinusoidal Chart Bar Charts March 02002 Chuck DiMarzio, Northeastern University
20
Some Resolution Charts (2)
Air Force ISO Bar Charts March 02002 Chuck DiMarzio, Northeastern University
21
Radial Target and Image
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Radial Target and Image Colorbar for all 20 40 60 80 100 120 140 160 180 Object Image 20 40 60 80 100 120 140 160 180 20 40 60 80 100 120 140 160 180 Point-Spread Function of System March 02002 Chuck DiMarzio, Northeastern University
22
Chuck DiMarzio, Northeastern University
Grating Equation sin(qd) 5 1 4 3 0.5 sin(qi) 2 1 -sin(qi) n=0 -0.5 -1 -2 -1 -100 100 200 -3 Reflected Orders Transmitted Orders degrees March 02002 Chuck DiMarzio, Northeastern University
23
Grating Fourier Analysis
Diffraction Pattern Sinc Slit Convolve Multiply Repetition Pattern Result Multiply Convolve Apodization Result March 02002 Chuck DiMarzio, Northeastern University
24
Chuck DiMarzio, Northeastern University
Laser Tuning Gain f Cavity Modes f qi March 02002 Chuck DiMarzio, Northeastern University
25
Acousto-Optical Modulator
Sound Source Absorber March 02002 Chuck DiMarzio, Northeastern University
26
The Spherical-Gaussian Beam
Gaussian Profile Rayleigh Range Diameter Radius of Curvature Axial Irradiance March 02002 Chuck DiMarzio, Northeastern University
27
Visualization of Gaussian Beam
w r z=0 Center of Curvature March 02002 Chuck DiMarzio, Northeastern University
28
Parameters vs. Axial Distance
-5 5 1 2 3 4 z/b, Axial Distance d/d , Beam Diameter -5 5 z/b, Axial Distance r /b, Radius of Curvature m4053 m4053 March 02002 Chuck DiMarzio, Northeastern University
29
Complex Radius of Curvature: Physical Results
March 02002 Chuck DiMarzio, Northeastern University
30
Chuck DiMarzio, Northeastern University
Making a Laser Cavity Make the Mirror Curvatures Match Those of the Beam You Want. March 02002 Chuck DiMarzio, Northeastern University
31
Sample Hermite Gaussian Beams
0:0 0:1 0:3 (0:1)+i(1:0) = “Donut Mode” 1:0 1:1 1:3 2:0 2:1 2:3 Most lasers prefer rectangular modes because something breaks the circular symmetry. 5:0 5:1 5:3 from matlab program m Note: Irradiance Images rendered with g=0.5 March 02002 Chuck DiMarzio, Northeastern University
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.