### arXiv:1908.04765 [quant-ph]AbstractReferencesReviewsResources

#### Tuning between photon-number and quadrature measurements with weak-field homodyne detection

G. S. Thekkadath, D. S. Phillips, J. F. F. Bulmer, W. R. Clements, A. Eckstein, B. A. Bell, J. Lugani, T. A. W. Wolterink, A. Lita, S. W. Nam, T. Gerrits, C. G. Wade, I. A. Walmsley

Published 2019-08-13Version 1

Variable measurement operators enable the optimization of strategies for testing quantum properties and the preparation of a range of quantum states. Here, we experimentally implement a weak-field homodyne detector that can continuously tune between performing a photon-number measurement and a field quadrature measurement on a quantum state $\hat{\rho}$. We combine $\hat{\rho}$ with a coherent state $|\alpha\rangle$ on a balanced beam splitter, and detect light at both output ports using photon-number-resolving transition edge sensors. We observe that the discrete difference statistics converge to the quadrature distribution of $\hat{\rho}$ as we increase $|\alpha|$. Moreover, in a proof-of-principle demonstration of state engineering, we show the ability to control the photon-number distribution of a state that is heralded using our weak-field homodyne detector.

**Comments:**12 pages, 10 figures; includes Supplemental Material

**Categories:**quant-ph