A Novel individual addressing system for ions in a micro-fabricated trap*

Trapped ions are one of the most promising platforms for the large-scale implementation of quantum information processing. For the realization of such a device, control over the state of individual qubits is necessary. Current implementations rely on acousto-optic deflectors, multi-channel acousto-optic modulators (AOMs) or micromirror devices for holographic beam shaping. Such implementations either suffer from high crosstalk, lack parallel addressing or the ability to control the frequency and phase of each beam. Here we describe the novel individual addressing system of our trapped-ion computer currently under construction. The system is designed for enabling Raman-based gates on 16 Ba+ ions. It consists of an array of laser-written waveguides that split the light into 16 channels and couple each into single mode fibers. Fiber-based AOMs provide control over the frequency, phase and amplitude of each channel and a micro-lens-based telescope maps the light from each fiber channel to an ion in the trap with low crosstalk. The use of such technology is enabled by the desirable energy level structure of Ba+, namely the visible S- to P-shell transition used for Raman operations.