1. M. Varvella - Virgo LALCascina, March 15-19, 2004 STATUS of SIGNAL RECYCLING SIMULATION at Virgo LAL Signal Recycling Code strategy Optical configurations investigated Link to other libraries Future steps

2. M. Varvella - Virgo LALCascina, March 15-19, 2004 SIGNAL RECYCLING PRINCIPLE 40 m Prototype in Caltech Power Recycling Mirror Signal Recycling Mirror (MSR) Cavities LASER Sensitivity Without Signal Recycling With Signal Recycling Optical Simulations Control Simulations Experimental work on site LAL contribution time domain

3. M. Varvella - Virgo LALCascina, March 15-19, 2004 FIELD ( methods : field creation, power) MIRROR ( methods : parameters verification) CAVITY ( methods : transmitted, reflected, stored fields) PHOTODIODE ( to be implemented ) …….. Other possible objects CODE STRATEGY in C++ OBJECTS Test Programs Use of objects for different configurations Fabry-Perot cavity Michelson ITF CITF 40 m + Signal Recycling Virgo Virgo + Signal Recycling ………. Examples :

4. M. Varvella - Virgo LALCascina, March 15-19, 2004 Simple Fabry-Perot Cavity CONFIGURATIONS - I Static behavior : OK !! Dynamic behavior : OK !! reflected field incident Field stored field transmitted field M1M2 L v = 0 v = 1 µm/s finesse ~ 45 ringing effect

5. M. Varvella - Virgo LALCascina, March 15-19, 2004 Double Fabry-Perot Cavity CONFIGURATIONS - II STATUS : Static and Dynamic behavior in progress Interesting in the search of methods to sum signals reflected field M1 M2M3 L l incident field transmitted field stored field l < L

6. M. Varvella - Virgo LALCascina, March 15-19, 2004 Interface to SIESTA Interface to E2E Interface to code for future detectors LINK TO OTHER LIBRARIES LAL SR library SIESTA library E2E library Future detectors

7. M. Varvella - Virgo LALCascina, March 15-19, 2004 Double Fabry-Perot Cavity Comparison of LAL Code with existing codes (E2E, SIESTA, Finesse) Signal Recycling investigation Test on 40 m (2004) Test on Virgo ? Suggestions ? FUTURE STEPS