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arXiv · 1905.08431

Fully tunable and switchable coupler for photonic routing in quantum detection and modulation

Vojtěch Švarc·Martina Nováková·Glib Mazin·Miroslav Ježek
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Abstract

Photonic routing is a key building block of many optical applications challenging its development. We report a 2$\times$2 photonic coupler with splitting ratio switchable by a low-voltage electronic signal with 10~GHz bandwidth and tens of nanoseconds latency. The coupler can operate at any splitting ratio ranging from 0:100 to 100:0 with the extinction ratio of 26 dB in optical bandwidth of 1.3 THz. We show sub-nanosecond switching between arbitrary coupling regimes including balanced 50:50 beam splitter, 0:100 switch, and a photonic tap. The core of the device is based on Mach-Zehnder interferometer in a dual-wavelength configuration allowing real-time phase lock with long-term sub-degree stability at single-photon level. Using the reported coupler, we demonstrate for the first time the perfectly balanced time-multiplexed device for photon-number-resolving detectors and also the active preparation of a photonic temporal qudit state up to four time bins. Verified long-term stable operation of the coupler at the single photon level makes it suitable for wide application range in quantum information processing and quantum optics in general.

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Vojtěch Švarc, Martina Nováková, Glib Mazin, Miroslav Ježek. 2019-12-19. Fully tunable and switchable coupler for photonic routing in quantum detection and modulation. https://doi.org/10.1364/ol.44.005844

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