1 / 21

Parametric Effects in a Macroscopic Optical Cavity

AIGO. Parametric Effects in a Macroscopic Optical Cavity. Sascha Schediwy schediwy@physics.uwa.edu.au. AIGO Workshop Thursday 6 th October. Optical Spring. Circulating Power. Frequency. Q reduction Q increase. Q Increase - Parametric Gain. Niobium Resonator. Cavity Properties Niobium

emmy
Download Presentation

Parametric Effects in a Macroscopic Optical Cavity

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. AIGO Parametric Effects in aMacroscopic Optical Cavity Sascha Schediwyschediwy@physics.uwa.edu.au AIGO WorkshopThursday 6th October

  2. Optical Spring CirculatingPower Frequency Q reductionQ increase

  3. Q Increase - Parametric Gain

  4. Niobium Resonator • Cavity Properties • Niobium • Qm = 1.562 (8)*105 • fmech = 780 Hz • meff = 32.3 g • l = 0.10m • Proxy Mirrors • R = 0.98 • F = 155 • roc = 10.0 m • Super Mirrors • R ~ 0.99968 (rated: 0.9994+) • F ~ 9800 (rated: 5200+) • roc = 1.0 m

  5. Yacca Gum Properties • viscous at 80°C+ • reversible bonds • dissolves in alcohol • relatively low loss • Q ~ 100 60°C 70°C 80°C 90°C

  6. Yacca Gum Bonding

  7. temp mirror 2 key: 3525 object position (mm) beam power (%) optical loss (%) temp mirror 1 Experimental Design

  8. Optical Error Signal Ringdown Ringdown Linear Fit time (s) time (s) (experimental results)

  9. Quality Factor Q = 0.700 ± 0.002 x105

  10. Proxy Mirror Q Modification F[rad] (N) Quality Factor (-) Mechanical Q k[opt] (N/m) Modified Q

  11. Super Mirror Q Modification F[rad] (N) Quality Factor (-) Mechanical Q (Hz) Damage Threshold Limited k[opt] (N/m) (Hz) (Hz) Laser Maximum

  12. Parametric Instability Tranquilisation • Model proposed by:Braginsky & Vyatchanin (Phys. Lett. A 293 (2002) 228-234)

  13. Any Question?

  14. Q Modification / Optical Spring Const.

  15. Circulating Power • Cavity Properties • Rayleigh Range / Beam Waist • R1 = R2 = 1.0 m • L = 0.1 m • Spot Size at Mirror ( z = 0.05 m )

  16. Circulating Power • Newport Supermirrors • Damage Threshold: • Maximum Circulating Power: • Maximum Input Power • R1 = R2 > 99.94% • T1 > 0.06%

  17. Radiation Pressure Force • Radiation pressure force for FP Cavity ≈ unity • let:

  18. Optical Spring Constant • substitute ABC back in x space in f space

  19. Cavity Alignment

  20. “Low Q” / “High Q” • Low Q – when the bandwidth is larger than ωm • High Q – when the bandwidth is smaller than ωm FWHM –ωm ωm FWHM –ωm ωm

More Related