Light spectral filtering based on spatial adiabatic passage

Abstract

We present the first experimental realization of a light spectral filter based on the spatial adiabatic passage technique. We demonstrate that a fully integrable CMOS-compatible system of three coupled identical total internal reflection silicon oxide waveguides with variable separation along their propagation direction can be used simultaneously as a low-and high-pass spectral filter within the visible range of wavelengths. Light is injected into the right waveguide, and after propagating along the system, long wavelengths are transferred into the left output, whereas short wavelengths propagate to the right and central outputs. The stopband reaches values up to 211 dB for the left output and approximately 220 dB for the right plus central outputs. The passband values are close to 0 dB for both cases. We also demonstrate that the filtering characteristics of the device can be controlled by modifying the parameter values, which define the geometry of the triple-waveguide system. However, the general filtering behavior of the system does not critically depend on technological variations. Thus, the spatial adiabatic passage filtering approach constitutes an alternative to other integrated filtering devices, such as interference or absorbance-based filters.

Robust and Broadband Optical Coupling by Topological Waveguide Arrays

“…Therefore, precise requirement in micro/nanofabrication is very stringent, which severely challenges current manufacturing technology. Great efforts have been made to solve the longstanding problem, such as compensation process by Mach–Zehnder interferometer, programmable solution for on‐demand fabrications, and adiabatic passage designs . These approaches usually require external intervention or strict parameter condition that have to sacrifice in some other important aspects, and there is still a high demand for devices with a naturally robust design.…”

“…Great efforts have been made to solve the longstanding problem, such as compensation process by Mach–Zehnder interferometer, programmable solution for on‐demand fabrications, and adiabatic passage designs . These approaches usually require external intervention or strict parameter condition that have to sacrifice in some other important aspects, and there is still a high demand for devices with a naturally robust design. More recently, the robust waveguiding and transportation based on TES have been proposed and demonstrated in silicon platform, showing the advantages of topological design in integrated photonic devices.…”

Spatial adiabatic passage processes in sonic crystals with linear defects

“…Nevertheless, the system can still be used to measure the phase difference between two beams by adjusting the normalization in Eqs. (17) and (18) and also calibrating the obtained outputs.…”

Photon pair generation and pump filtering in nonlinear adiabatic waveguiding structures

“…In this Letter, we show that, by employing adiabatic waveguide coupling [12,13], we can generate SPDC photon pairs entangled in the degree of modal entanglement, while simultaneously keeping the filtered photon states separable from the photons in the pumped waveguide. Our proposed scheme reveals the possibility of combining flexible reconfigurable quantum state generation and spatial filtering of the pump beam in an integrated photonic chip.…”