1 / 39

FOCUSING OPTICS

FOCUSING OPTICS. Spherical lenses. Achromatic doublets. Parabolic mirrors. Chromatic Aberration only. No aberration. Slide 2. Cheap singlets may be better than expensive aspherics!. Chromatic and spherical aberration. Parabola: curve at equal distance from a point (F) and line.

billyew
Download Presentation

FOCUSING OPTICS

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FOCUSING OPTICS Spherical lenses Achromatic doublets Parabolic mirrors

  2. Chromatic Aberration only No aberration Slide 2 Cheap singlets may be better than expensive aspherics! Chromatic and spherical aberration

  3. Parabola: curve at equal distance from a point (F) and line y = ax2 F B A O x d E D

  4. Parabolic mirror: why do all rays perpendicular to the directrix converge at the focus F? F y=2ax A x x O 2 C d D E …because ACF is isoceles, hence AF=CF and AE=y+d so OF = d

  5. Off-axis parabolic mirror F

  6. Group delay Wave front and energy front db tan g = l db = angular dispersion g = tilt of energy front dl dl Group velocity dispersion There is also a relation between GVD and angular dispersion

  7. S’W Q S0, SW PW rW a L r0 P0 S’0 Whether considering group delays or group velocity dispersion (GVD), we will consider sufficiently broad beams, and sufficiently short propagation distances Lp behind the element, such that diffraction effects can be neglected.

  8. S’W Q S0, SW PW rW a L r0 P0 S’0

  9. The most widely used optical devices for angular dispersion are prisms and gratings. To determine the dispersion introduced by them we need to specify not only a(W), but also the optical surfaces between which the path is being calculated. The ``dispersion'' of an element has only meaning in the context of a particular application, that will associate reference surfaces to that element.

  10. a h L A B L g C (R)

  11. 2

  12. For a collimated beam, a logical reference plane is normal to the beam Pairs of prisms 2nd Element (reversed) Reference plane B Reference plane A 1st Element

  13. O H A q0 q3 B q2 q1 D t2 W t W+dW q6 q4 q5 q0 B’ = q3 A’ A’’ a u O’ s

  14. ceo Phase delay

  15. O H A q0 q3 B q2 q1 D t2 W t W+dW q6 q4 q5 q0 B’ = q3 A’ A’’ a u O’ s

  16. O q3 A B q2 t q4 B’ A’ W = q3 A’’ t2 W+dW a O’ s

  17. dq3 q6 q5 q7 = q0 B’ A’ Q a-q2 R B’’ T A’’ S q5 u q4 H’ B’’’ A’’’ a O’

  18. W O Lg a X A’ q0 A W + dW q1 dq1 A’’ q1 O’’’ g

  19. Angular Glass:

  20. O H A q3 B q1 L D W q6 q4 q5 q0 B’ = q3 A’ a O’

  21. Paper of Fork WRONG, because implies that the separation between the prisms L has both a positive and negative effect. the only optical path considered is L or the path between the two prisms; the beam displacement after the second prism is not calculated. is only for the case of tip to tip propagation in the prisms

  22. ceo Phase delay { For a pair of prisms we found: For gratings, the simple rule applies also

  23. 4. Gratings pairs for pulse stretching – what are the adjustable Parameters? Wavelength? l Fixed Groove spacing d? Larger than l Diffraction angle large (Littrow configuration) Size of grating: pulse length. Grating order

  24. db’ C P W d C0 P0 G2 b’ G1 b b A

  25. Oscillators and Amplifiers

  26. OC Oscillators M2 TS To Timing Logic M1 G P1 S PD FM P2 S EM

  27. Stretcher

  28. Mode-Matched Stretched Seed s-polarized TS p-polarized Relay Imaged Pump Beam TFP PC

  29. Output to compressor Relay-Imaged Nd:YAG Pump TS Divergence-adjusted seed from Regenerative Amplifier Relay-Imaged Nd:YAG Pump Multipass amplifier

  30. Compressor Top View G G M

More Related