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Semiconductor Photon Detectors (Ch 18). Semiconductor Photon Sources (Ch 17). Lasers (Ch 15). Photons in Semiconductors (Ch 16). Laser Amplifiers (Ch 14). Photons & Atoms (Ch 13). Quantum (Photon) Optics (Ch 12). Resonators (Ch 10). Electromagnetic Optics (Ch 5). Wave Optics (Ch 2 & 3).
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Semiconductor Photon Detectors (Ch 18) Semiconductor Photon Sources (Ch 17) Lasers (Ch 15) Photons in Semiconductors (Ch 16) Laser Amplifiers (Ch 14) Photons & Atoms (Ch 13) Quantum (Photon) Optics (Ch 12) Resonators (Ch 10) Electromagnetic Optics (Ch 5) Wave Optics (Ch 2 & 3) Ray Optics (Ch 1) Optics Physics Optoelectronics Introduction to Optical Electronics
Wave Optics *A(r) varies slowly with respect to
Gaussian Beam Width W(z) 20 z
2W0 2W R z Exercise 3.1-3: Determination of a Beam with Given Width and Curvature Given W and R, determine z and W0.
R2 W2 R1W1 d Exercise 3.1-4: Determination of the width and curvature at one point given the width and curvature at another point Given the width (W1) and curvature (R1) at a point, determine the width (W2) and curvature (R2) at a distance d to the right. Given: = 1 m R1 = 1 m W1 = 1 mm d = 10 cm to the right Find R2 and W2 at d.
z2 z1 R2 R1 d Exercise 3.1-5: Identification of a Beam with Known Curvatures at Two Points A Gaussian beam has radii of curvature R1 and R2 at two points on the beam separated by a distance d. Verify the equations for z1, z0 and W0.
z´ z 0 W0 W´0 ´0 z z0 z´0 W R W´ R´ Transmission through a Thin LensGaussian Beam
Exercise 3.2-2 • A Gaussian beam is transmitted through a thin lens of focal length f. • Show that the locations of the waists of the incident and transmitted beams, z and z´, are related by: • The beam is collimated by making the location of the new waist z´ as distant as possible from the lens. This is achieved by using the smallest ratio z0 / f , show that the optimal value of z for collimation is z = f + z0. z´ z W´0 W0 z z0 z´0 W R W´ R´
W1 R1 q1 W2 R2 q2 Transmission Through Optical ComponentsGaussian Beam Applies to thin optical components and to propagation in homogeneous medium of paraxial waves
Transmission Through Optical ComponentsGaussian Beam W1 W′ z W1 R1 q1 W' R' q' Find the Radius of Curvature and spot size just to the right of the lens (R′ and W′) if the incident Gaussian Beam is planar on the lens.
zm W′ W02 W01 z What is the minimum spot size achievable with a thin lens? Transmission Through a Thin LensGaussian Beam W1 R1 q1 W' R' q'
Hermite-Gaussian Waves TEM0,0 • Amplitude (black) and Intensity (red) distribution along x-axis • Higher order modes become wider with (l,m): 2W(z) is just a scale factor for higher order modes • TEM0,0 will be most intensely focused beam (Gaussian Beam) TEM1,0 TEM2,0
TEM0,0 TEM0,1 TEM0,2 TEM1,1 TEM1,2 TEM2,2 Hermite-Gaussian Beams