A promising technique in optical super-resolution microscopy is the illumination of the sample by a highly localized beam, a photonic jet (also called photonic nanojet). We propose a method of computation of incident field amplitude and phase profiles that produce photonic jets at desired locations in the near field after interaction with a fixed micro-scale dielectric lens. We also describe a practical way of obtaining the incident field profiles using spatial light modulators. We expect our photonic jet design method to work for a wide range of lens shapes, and we demonstrate its application numerically using two-dimensional micro-lenses of circular and square cross-sections. We furthermore offer a theoretical analysis of the resolution of photonic jet design, predicting among other that a larger lens can produce a narrower photonic jet. Finally, we give both theoretical and numerical evidence that the waist width of the achieved designed jets is increasing linearly and slowly over a large interval of radial distances. With uniform plane wave illumination, the circular two-dimensional micro-lens produces a similar-sized jet at a fixed radial distance, while the square lens does not form a jet at all. We expect our steerable optical photonic jet probe to enable highly localized adaptive real-time measurements and drive advances in super-resolution optical microscopy and scatterometry, as well as fluorescence and Raman microscopy. Our relatively weak peak jet intensity allows application in biology and health sciences, which require high resolution imaging without damaging the sample bio-molecules.

The lateral and vertical resolution in conventional optical microscopy is restricted by fundamental diffraction limits. One direction towards super-resolution optical microscopy is the use of photonic nanojets (PNJs) for sample illumination. Here, the aim is to exploit the high spatial localization of PNJs to allow measurements of sub-classical particles and features in spite of their small size compared to the operating wavelength. The applications of super-resolution methods include fluorescence and Raman microscopy, scatterometric measurements, and optical imaging. As a step towards PNJ scanning microscopy, we here apply our recently proposed method for fast and precise steering of PNJs over a large dynamical range in the near field. In a proof-of-concept computation, we use the steerable optical probe to extract information on structures beyond the classical lateral and vertical resolution limits.