1 / 13

FSS

FSS. Frequency Stabilisation System. Overview. Why we need FSS: Stabilise the optical frequency of fibre laser to + 3 kHz Use Rb frequency standard at 780 nm access from 1560 nm SHG. Tuning control. 0-200 V Tuning over 10 GHz + 70 µV ≡ + 3 kHz Stabilise to 3 kHz

alana-fulton
Download Presentation

FSS

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. FSS Frequency Stabilisation System

  2. Overview Why we need FSS: • Stabilise the optical frequency of fibre laser to +3 kHz • Use Rb frequency standard at 780 nm access from 1560 nm SHG

  3. Tuning control 0-200 V Tuning over 10 GHz +70 µV ≡ +3 kHz Stabilise to 3 kHz Stabilise circuit temperature All voltage variations due to lock-in signals Peltier Cooler

  4. Peltier Cooler • Heat pump uses Peltier-Seebeck effect • Array of p and n type semiconductors • Transfers heat from one face to the other • depending on current flow

  5. Experiments • Evaluation board which controlled Peltier test set-up • Experiments done by adjusting set-point voltage and looking at how the Peltier temperature changed • Measured the voltage across the module; THERM voltage, and convergence

  6. Results • 0.7 V-4 A power supply to get 25 °C • Gradient of linear region agreed with specification • Convergence between THERM and set-point deviated further from 100 µV at higher temperatures

  7. Hall Probe • Magnetic field • Single turn inductive loop in lines of magnetic flux

  8. 5²S1/2 → 5²P3/2 • Magnetic field affect the energy of transition • Ambient fields • 4-layer cylindrical shield lined with mu-metal

  9. Results

  10. Opto-isolator: • Top 4 frequency bits set by DIP switch • FPGA controls bits 8-26

  11. Plans • Test tuning part of system • Spectrum analyser

More Related