Dynamic Gain of an Optical Transistor

Paul Mandel

P. Nardone, Paul Mandel

We study the semiclassical mean field limit equations describing an optical transistor in the case of dominant dispersive optical bistability/1/ where n is the field-induced refraction index, I the input intensity and θ the field-cavity detuning. All variables are scaled.

Игорь Евгеньевич Проценко, Luigi A. Lugiato

Brad Dinardo

The work of this dissertation falls into two broad categories. In the first part, I describe loading a single atom from a reservoir into a blue-detuned crossed vortex bottle beam trap using a dynamic 1D optical lattice. The lattice beams are frequency chirped using acousto-optic modulators, which causes the lattice to move along its axial direction and behave like an optical conveyor belt. A stationary lattice is initially loaded with approximately 6000 atoms from a reservoir, and the conveyor belt transports them 1.1 mm from the reservoir to a bottle beam trap, where a single atom is loaded via light-assisted collisions. Photon counting data confirm that an atom can be delivered and loaded into the bottle beam trap 13.1% of the time. In part II, I describe a theory and experiment in the field of atomtronics that displays a coherent gain mechanism for a triple-well matterwave transistor oscillator. I start with a well-established semi-classical description of an atomtronic transistor but model the system using a many-body formalism. The quantum model predicts interesting physics when the atoms flowing through the transistor have sufficiently low enough temperatures such that the motional state of a dipole oscillating BEC, placed in the transistor itself, couples atom transitions between high lying transistor energy eigenstates. In this regime, the coupling gives rise to a new gain mechanism that increases the flux of matterwaves flowing out of the transistor system, compared to when the coupling is absent. Our experiments suggest that the gain mechanism is coherent and increases the spread of matterwave momenta that flows out of the transistor.

Paul Mandel

Charles S. Adams

An all-optical transistor is a device in which a gate light pulse switches the transmission of a target light pulse with a gain above unity.The gain quantifies the change of the transmitted target photon number per incoming gate photon.We study the quantum limit of one incoming gate photon and observe a gain of 20.The gate pulse is stored as a Rydberg excitation in an ultracold gas.The transmission of the subsequent target pulse is suppressed by Rydberg blockade, which is enhanced by a Förster resonance.The detected target photons reveal in a single shot with a fidelity above 0.86 whether a Rydberg excitation was created during the gate pulse.The gain offers the possibility to distribute the transistor output to the inputs of many transistors, thus making complex computational tasks possible.