Elaheh Zamani’s research aims to unravel the fundamental limits of phase measurements, classical and quantum. The experimental model involves an Optical Parametric Oscillator harmonically pumped by a frequency comb. The present system has shown a 50 picoradian resolution for a measuring time of 1000s. Beyond the straightforward improvements to be implemented by long and short term stabilization, fundamental questions remain to be addressed as to the sources of noise. The various contributions to the measurement uncertainty are mechanical and thermal noise, OPO noise which include vacuum fluctuations and pump noise. The latter frequency comb noise should also have a quantum limit that remains to be analyzed. One the classical limit of noise has been achiever, can phase squeezing be achieved to push further the resolution limits?