arXiv subjects

Christopher DeRose

Publications and source records attributed to Christopher DeRose.

4 recordsLinked to original sources

arXiv2022

High-Performance Silicon Photonic Single-Sideband Modulators for Cold Atom Interferometry

The most complicated and challenging system within a light-pulse atom interferometer (LPAI) is the laser system, which controls the frequencies and intensities of multiple laser beams over time to configure quantum gravity and inertial sensors. The main function of an LPAI laser system is to perform cold-atom generation, state-preparation, state-selective detection and to generate coherent two-photon process for the light-pulse sequence. Substantial miniaturization and ruggedization of the laser system can be achieved by bringing most key functions of the laser system onto photonic integrated circuit (PIC). We demonstrate a high-performance silicon photonic suppressed-carrier single-sideband (SC-SSB) modulator at 1560 nm, which can dynamically frequency shift within the LPAI. With independent RF-channel control, we study the imbalances in both the optical and RF phases/amplitudes to reach 30 dB carrier-suppression, unprecedented 47.8 dB sideband-suppression at peak conversion-efficiency: -6.846 dB (20.7 %). Using a silicon photonic SSB-modulator, we demonstrate cold-atom generation, state-selective detection, and atom interferometer fringes to estimate gravitational acceleration, $g \approx 9.77 \pm 0.01 \,\rm{m/s^2}$, in a Rubidium ($^{87}$Rb) atom system.

physics.optics↗

arXiv2021

Characterization of Suspended Membrane Waveguides towards a Photonic Atom Trap Integrated Platform

We demonstrate an optical waveguide device, capable of supporting the high, in-vacuum, optical power necessary for trapping a single atom or a cold atom ensemble with evanescent fields. Our photonic integrated platforms, with suspended membrane waveguides, successfully manages optical powers of 6 mW (500 um span) to nearly 30 mW (125 um span) over an un-tethered waveguide span. This platform is compatible with laser cooling and magneto-optical traps (MOTs) in the vicinity of the suspended waveguide, called the membrane MOT and the needle MOT, a key ingredient for efficient trap loading. We evaluate two novel designs that explore critical thermal management features that enable this large power handling. This work represents a significant step toward an integrated platform for coupling neutral atom quantum systems to photonic and electronic integrated circuits on silicon.

quant-ph↗

arXiv2017

Metropolitan quantum key distribution with silicon photonics

Photonic integrated circuits (PICs) provide a compact and stable platform for quantum photonics. Here we demonstrate a silicon photonics quantum key distribution (QKD) transmitter in the first high-speed polarization-based QKD field tests. The systems reach composable secret key rates of 950 kbps in a local test (on a 103.6-m fiber with a total emulated loss of 9.2 dB) and 106 kbps in an intercity metropolitan test (on a 43-km fiber with 16.4 dB loss). Our results represent the highest secret key generation rate for polarization-based QKD experiments at a standard telecom wavelength and demonstrate PICs as a promising, scalable resource for future formation of metropolitan quantum-secure communications networks.

quant-ph↗

arXiv2015

Hybrid Lithium Niobate and Silicon Photonic Waveguides

We describe a hybrid lithium niobate (LN) / silicon (Si) optical waveguiding platform at near infrared wavelengths. Various optical circuit elements, such as waveguides, bends, and couplers are demonstrated in two hybrid cross sections, A and B, with different LN confinement factors (32% and 90%, respectively) of the fundamental quasi TE mode. Such a large LN confinement factor is achieved with adiabatic tapers that preserve the symmetry of the fundamental quasi TE mode and prevent mode rotation. We find the average propagation loss in cross section B to be 4.3 dB/cm with a standard deviation of 2.1 dB/cm, comparable with a 3 um SiO2 clad (in place of LN) Si waveguide whose average propagation loss was 3.1 dB/cm with a standard deviation of 2.1 dB/cm.

physics.optics↗