The microlens arrays (MLAs) are widely utilized for various applications. However, when the lens size and the spacing between two adjacent microlenses are of the length scale of the working wavelength, the diffraction effect plays a vital role in the final focusing performance. We suggest a kind of broadband metallic planar microlenses, based on which the ultra-compact microlens arrays are also...

Phase difference regression (PDR) was widely utilized to estimate Direction-of-Arrival (DOA) for linear arrays because of its high time resolution and high computational efficiency. However, conventional regression methods were seldom reported to estimate DOA using planar arrays. This paper proposes a regression method to derive DOA from all phase differences on all frequencies for a planar arr...

In this paper a way to achieve virtual two-dimensional planar array for sonar systems using the multiple input output (MIMO) principle is presented. The time delay information of can be used imaging sonars and allows localization scatterers in three-dimensional space. conventional single (SIMO) sonar, would achieved transmitter receiver consisting N² hydrophones, arranged as rectangular N × mat...

A 3D flexible multichannel microprobe array was designed, fabricated and tested. Since each probe had several recording pads, the probe array could be used to measure neural activity at various depths in the brain. They were batch fabricated with interconnections, using a specific folding process to fold the planar probe structures. This flexible probe array was inserted into a rat’s brain with...

We demonstrate that light propagation in waveguide arrays that include PT-symmetric structures can exhibit strongly nonlocal sensitivity to topology of the array at fixed other parameters. We consider an array composed of lossless waveguides, that includes a pair of PT-symmetric waveguides with balanced gain and loss, and reveal that PT-symmetry breaking thresholds are different for planar and ...

We analyze polarization changes of light diffracted on a planar chiral array from the standpoint of the Lorentz reciprocity lemma and find biorthogonality in the polarization eigenstates for waves diffracting though the grating in the opposite direction. Both reciprocal and nonreciprocal components in the polarization azimuth rotation of the diffracted light are identified. The structural chira...

Compressive Sensing (CS) has demonstrated to be particularly adapt for dealing with the directions-of-arrival (DoAs) estimation of electromagnetic signals impinging on an array of sensors. Unlike deterministic CS methods, the Bayesian CS (BCS) allows to overcome some theoretical limitations of the CS, such to enable a reliable and versatile DoAs estimation tool able to work with different array...