Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Diagnosis of Pulsed Squeezing in Multiple Temporal Modes



Scott C. Glancy, Emanuel H. Knill, Thomas Gerrits, Tracy S. Clement, Martin J. Stevens, Sae Woo Nam, Richard P. Mirin


When one makes squeezed light by downconversion of a pulsed pump laser, many temporal / spectral modes are simultaneously squeezed by different amounts. There is no guarantee that any of these modes matches the pump or the local oscillator used to measure the squeezing in homodyne detection. Therefore the state observed in homodyne detection is not pure, and many photons are present in the beam path that do not lie in the local oscillator's mode. These problems limit the fidelity of quantum information processing tasks with pulsed squeezed light. I will describe our attempts to make coherent state superpositions (sometimes called "cat states") using photon subtraction from squeezed light, the problems caused by multimode squeezing, and methods to characterize the contents of the many squeezed modes.


Schrodinger cat state, quantum state tomography, quantum state estimation, Gaussian state, squeezed state
Created August 26, 2008, Updated February 19, 2017