The 1.45" cavities have arrived. So I think it is a good time I layout the plan for the next phase of the experiment:

To Do:

• Design optic layout for 2-laser setup
• Try assemble the cavities with our SiO2/Ta2O5 mirrors
• modify seismic stack / design for holding the cavities
• getting AlAs/GaAs coating on the substrates
• find substrate with AdvLIGO coating
• Choose resonant frequency for 2nd PMC, and 2nd cavity

fig2: proposed new setup with 2 laser sources

Since we want to upgrade the current setup to 2-laser setup, we need to find:

• another NPRO
• another PMC
• broad band EOM, and two resonant EOMs (one for locking PMC, one for locking to the cavity)
• RFPD, servo, oscillator for locking 2nd PMC to NPRO
• RFPD for 2nd cavity (with the correct resonant frequency)
• second oscillator for locking NPRO to the cavity (we can reuse the marconi for AOM)
• another servo for PMC (I think there is one spare that we used for driving a PZT, I'll check)