Karr04a

Squeezing in semiconductor microcavities in the strong-coupling regime. J. Ph. Karr, A. Baas, R. Houdré and E. Giacobino in Phys. Rev. A 69:R031802 (2004).  What the paper says!?

This page is still in progress.

This is the first report of polariton squeezing.

Specifically, they «report an experimental demonstration of quantum noise reduction in a semiconductor microcavity» by exciting the microcavity at normal incidence (as opposed to at the magic angle):

In this configuration, the nonlinear mechanism is quasidegenerate four-wave mixing between polaritons with $k\approx0$.

Later in the text they make the more explicit claim that «we report the observation of polariton squeezing.» Their main result:

The polariton squeezing generates squeezing of the outgoing light, that is measured to be 4%.

Difference between polaritons and Kerr media:

Unlike experiments using transparent optical Kerr media, excitation in a microcavity is resonant both with the cavity and with the nonlinear medium. As a consequence, the squeezing rate is expected to be reduced due to the excess noise added by the polariton photoluminescence.

They first attribute theoretical proposals early in the text for quantum wells & microcavities to Refs. 

Several recent theoretical studies have pointed out the possibility to generate squeezed states of light by using excitonic nonlinearities in quantum wells or microcavities [3–5].

and then [confusingly] later on again, more specifically to polaritons, in Refs. plus a text by Giacobino in C.R. Phys. not easily locatable. They don't cite Ref. .

Regarding similarities to other optical systems in Refs. 

An early mention of polariton QIP: «Polariton squeezing opens the way to the use of semiconductor microcavities in the field of quantum information»