Laser written waveguide photonic quantum circuits

Abstract

We report photonic quantum circuits created using an ultrafast laser processing technique that is rapid, requires no lithographic mask and can be used to create three-dimensional networks of waveguide devices. We have characterized directional couplers--the key functional elements of photonic quantum circuits--and found that they perform as well as lithographically produced waveguide devices. We further demonstrate high-performance interferometers and an important multi-photon quantum interference phenomenon for the first time in integrated optics. This direct-write approach will enable the rapid development of sophisticated quantum optical circuits and their scaling into three-dimensions.

High-fidelity operation of quantum photonic circuits

“…[14][15][16][17]25 While high fidelity single qubit operations have been demonstrated in this architecture, 17 two photon logic gate operation, including quantum interference, below relevant EPG thresholds has not yet been demonstrated.…”

“…13 Integrated photonics-waveguide circuits lithographically patterned on-chip-holds great promise for miniaturizing and scaling quantum logic circuits, [14][15][16] and high fidelity single-qubit operations have already been demonstrated. 17 However, the crucial two-qubit operations required for more general quantum information protocols have yet to be demonstrated at high fidelity levels.…”

Atom–light interactions in photonic crystals

“…At a minimum, the further migration to photonic crystal structures should allow the relevant parameters associated with these paradigms to be pushed to their limits 26 and greatly facilitate scaling. For example, modern lithographic processing can create nanoscopic dielectric waveguides and resonators with optical quality factors Q410 6 and with efficient coupling among heterogeneous components [30][31][32][33][34][35] .…”

Experimental scheme for qubit and qutrit symmetric informationally complete positive operator-valued measurements using multiport devices

“…Integrated optics technology offers a solution to these shortcomings by providing a waveguide-based architecture that achieves compact, efficient, and stable quantum optical performance. Physical realizations of integrated optics include silica-based planar lightwave circuit interferometers fabricated on a semiconductor chip [18][19][20][21][22][23][24], periodically poled lithium niobate waveguides in standard fiber optics technology [25][26][27][28][29] and the direct-write femtosecond laser technique for manufacturing optical waveguides in dielectric materials [30][31][32], which allows one to realize three-dimensional photonic circuits, in contrast with the flat architecture of conventional lithography.…”