A Super-Condenser for Labelfree Nanoscopy

Abstract

Labelfree nanoscopy encompasses optical imaging with resolution in the 100 nm range using visible wavelengths. Here, we present a labelfree nanoscopy method that combines Fourier ptychography with waveguide microscopy to realize a 'super-condenser' featuring maximally inclined coherent darkfield illumination with artificially stretched wave vectors due to large refractive indices of the employed Si${}_3$N${}_4$ waveguide material. We produce the required coherent plane wave illumination for Fourier ptychography over imaging areas 400 $\mu$m${}^2$ in size via adiabatically tapered single-mode waveguides and tackle the overlap constraints of the Fourier ptychography phase retrieval algorithm two-fold: firstly, the directionality of the illumination wave vector is changed sequentially via a multiplexed input structure of the waveguide chip layout and secondly, the wave vector modulus is shortend via step-wise increases of the illumination light wavelength over the visible spectrum. We validate the method via in silico and in vitro experiments and provide details on the underlying image formation theory as well as the reconstruction algorithm.

References in corpus (6)

• Wide-field, high-resolution Fourier ptychographic microscopy
• All-optical signal processing platforms for CMOS compatible integrated nonlinear optics
• Dispersion engineered high-Q silicon Nitride Ring-Resonators via Atomic Layer Deposition
• On-Chip Integrated Quantum-Dot Silicon-Nitride Microdisk Lasers
• Analysis of Fourier ptychographic microscopy with half of the captured images
• Design and optimization of optical modulators based on graphene-on-silicon nitride microring resonators

Cited by in corpus (4)

• Scalable universal tunable virtual-wavevector spatial frequency shift (TVSFS) super-resolution imaging
• On-chip TIRF nanoscopy by applying Haar wavelet kernel analysis on intensity fluctuations induced by chip illumination
• Label-free chip-based evanescent light scattering super-resolution and superior-contrast optical microscopy (cELS)
• Terahertz non-label subwavelength imaging with composite photonics-plasmonics structured illumination