Amplification sharing of non-degenerate modes in an elliptical-core few-mode erbium-doped fiber.

We report on the study of a possible first step integration of mode division multiplexed optical component for single-mode fiber networks. State-of-the-art on few-mode erbium-doped fiber amplifiers is used to integrate the amplification function in a single component, which is expected to save energy in comparison to parallelized active components. So as to limit the impact of modal cross-talk, an elliptical-core few-mode erbium-doped fiber has been used to assemble an amplifier sharing setup for different single mode fibers, using non-degenerate modes.

Efficient and mode selective spatial mode multiplexer based on multi-plane light conversion.

We designed and built a new type of spatial mode multiplexer, based on Multi-Plane Light Conversion (MPLC), with very low intrinsic loss and high mode selectivity. In this first demonstration we show that a typical 3-mode multiplexer achieves a mode selectivity better than -23 dB and a total insertion efficiency of -4.1 dB (optical coating improvements could increase efficiency to -2.

Programmable multimode quantum networks.

Entanglement between large numbers of quantum modes is the quintessential resource for future technologies such as the quantum internet. Conventionally, the generation of multimode entanglement in optics requires complex layouts of beamsplitters and phase shifters in order to transform the input modes into entangled modes. Here we report the highly versatile and efficient generation of various multimode entangled states with the ability to switch between different linear optics networks in real time.

Optical pattern recognition via adaptive spatial homodyne detection.

We present an experimental demonstration of an optical pattern recognition scheme based on spatial homodyne detection. Our scheme is adaptive, all-optical, utilizes a single-element photo-detector, and provides a single parameter readout to quantify the efficacy of pattern recognition, thereby allowing very fast pattern recognition speeds. The spatial homodyne detector was applied to the identification of one- and two-dimensional phase profiles.

Programmable unitary spatial mode manipulation.

Free space propagation and conventional optical systems such as lenses and mirrors all perform spatial unitary transforms. However, the subset of transforms available through these conventional systems is limited in scope. We present here a unitary programmable mode converter (UPMC) capable of performing any spatial unitary transform of the light field.

Entangling the spatial properties of laser beams.

Position and momentum were the first pair of conjugate observables explicitly used to illustrate the intricacy of quantum mechanics. We have extended position and momentum entanglement to bright optical beams. Applications in optical metrology and interferometry require the continuous measurement of laser beams, with the accuracy fundamentally limited by the uncertainty principle.