We experimentally performed adaptive phase estimation using time-symmetric quantum smoothing for a stochastically varying phase on continuous wave coherent beam. We demonstrate better accuracy than conventional methods.
—This brief introduces a delayed differential feedback chaos generator with a programmable feedback element. The pro-grammable feedback allows us to implement an arbitrary nonlin-earity or modulate the feedback delay time. Delayed differential feedback systems have been suggested for secure communications, and the flexibility of the programmable system is… (More)
We present a method for synchronization of chaos generators based on transmission of an analog chaotic waveform in a digital form. Experimental comparisons between digital and analog transmission of chaos from a delayed differential feedback system are performed. Synchronization is demonstrated to be between 18 and 39 dB (or equivalently 63 to 7943 times)… (More)
This paper considers the application of integral Linear Quadratic Gaussian (LQG) optimal control theory to a problem of cavity locking in quantum optics. The cavity locking problem involves controlling the error between the laser frequency and the resonant frequency of the cavity. A model for the cavity system, which comprises a piezo-electric actuator and… (More)
Homodyne locking is a new approach to frequency-locking an OPO-based squeezed-vacuum source and its driving laser. It is cheap, easy to implement, subsequent measurements are automatically phase-locked, and it is uniquely a sub-QNL frequency discriminator.
Frequency locking of an optical cavity using a time-varying kalman filtering approach, " IEEE Trans. Control Syst. Tech., 2013. In print.  S. Z. Sayed Hassen, " A robust approach to the load frequency control problem with speed regulation uncertainty, " Int. Optimal frequency regulation of a two-area power system, " in IEEE Inter. A time-varying Kalman… (More)
We demonstrate squeezing-enhanced adaptive optical phase estimation for a stochastically varying phase. By using a continuous-wave phase squeezed beam, estimation accuracy is improved by a factor of 1.4 compared to a coherent beam case.
We demonstrate the measurement of a “squeezing comb”, the time-resolved homodyne detection of the first twelve vacuum squeezing sidebands of an optical parametric oscillator, and propose its use as a multiplexed quantum communications channel.