Gain-Induced Group Delay in Spontaneous Parametric Down-Conversion.

Strongly driven nonlinear optical processes such as spontaneous parametric down-conversion and spontaneous four-wave mixing can produce multiphoton nonclassical beams of light which have applications in quantum information processing and sensing. In contrast to the low-gain regime, new physical effects arise in a high-gain regime due to the interactions between the nonclassical light and the strong pump driving the nonlinear process. Here, we describe and experimentally observe a gain-induced group delay between the multiphoton pulses generated in a high-gain type-II spontaneous parametric down-conversion source.

Programmable Photonic Quantum Circuits with Ultrafast Time-Bin Encoding.

We propose a quantum information processing platform that utilizes the ultrafast time-bin encoding of photons. This approach offers a pathway to scalability by leveraging the inherent phase stability of collinear temporal interferometric networks at the femtosecond-to-picosecond timescale. The proposed architecture encodes information in ultrafast temporal bins processed using optically induced nonlinearities and birefringent materials while keeping photons in a single spatial mode.

Ultratunable Quantum Frequency Conversion in Photonic Crystal Fiber.

Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an ultrabroad (1226-1408 nm) range in a group-velocity-symmetric photonic crystal fiber, covering over 150 independent frequency bins. The target wavelength is controlled by tuning only a single pump laser wavelength.

Toward a Quantum Memory in a Fiber Cavity Controlled by Intracavity Frequency Translation.

We propose a quantum memory protocol based on trapping photons in a fiber-integrated cavity, comprised of a birefringent fiber with dichroic reflective end facets. Photons are switched into resonance with the fiber cavity by intracavity Bragg-scattering frequency translation, driven by ancillary control pulses. After the storage delay, photons are switched out of resonance with the cavity, again by intracavity frequency translation.

Carving out configurable ultrafast pulses from a continuous wave source via the optical Kerr effect.

Wavelength-tunable, time-locked pairs of ultrafast pulses are crucial in modern-day time-resolved measurements. We demonstrate a simple means of generating configurable optical pulse sequences: sub-picosecond pulses are carved out from a continuous wave laser via pump-induced optical Kerr switching in 10 cm of a commercial single-mode fiber. By introducing dispersion to the pump, the near transform-limited switched pulse duration is tuned between 305-570 fs.