Measuring the topological charge (TC) of optical vortex beams by the edge-diffraction pattern of a single plate is proposed and demonstrated. The diffraction fringes can keep well discernible in a wide three-dimensional range in t

Security is one of the key issues in communications, but it has not attracted much attention in the field of underwater wireless optical communication (UWOC). This Letter proposes a UWOC encryption scheme with orthogonal frequency

Visible light communication (VLC) based on the micro light emitting diode (micro-LED) has attracted increasing attention owing to its high bandwidth, low power consumption, and high security. Compared with semi-polar or non-polar

Terahertz metasurfaces have great applications for efficient terahertz modulation, but there are still problems in designing terahertz metadevices in terms of complexity and inefficiency. Herein, we demonstrate an inversely-design

A high-sensitivity DC magneto-optical Kerr effect (MOKE) apparatus is described in this Letter. Via detailed analysis on several dominating noise sources, we have proposed solutions that significantly lower the MOKE noise, and a s

An effective way to fabricate high-quality (Q) silicon microcavities on-chip is proposed and studied. Our fabrication technique consists of two significant steps: (1) patterning a special silicon micro-pillar by Bosch processes an

We demonstrate a simple method to obtain accurate optical waveforms with a gigahertz-level programmable modulation bandwidth and a watt-level output power for wideband optical control of free atoms and molecules. Arbitrary amplitu

A highly efficient milli-joule-level Q-switched Tm,La:CaF2 laser is experimentally demonstrated. By employing an acousto-optic modulator, the diode-pumped pulsed lasers are stably operated at repetition rates ranging from 500 Hz t

Ince–Gaussian (IG) beams, as eigenfunctions of the paraxial wave equation in elliptical coordinates, are attracting increasing interest owing to their propagation-invariant and full-field properties. Optical amplification via para

Weak RF signal detection with high resolution and no blind zone based on directly modulated multi-mode optoelectronic oscillation has been proposed. The high-sensitivity optical modulators and optical filters are avoided because m

A stimulated emission depletion is capable of breaking the diffraction limit by exciting fluorescent molecules with a solid Gaussian beam and quenching the excited molecules with another donut beam through stimulated emission. The

Lithium niobate (LN) metasurfaces have emerged as a new platform for manipulating electromagnetic waves. Here, we report a fabrication technique for LN nano-grating metasurfaces by combining focused ion beam (FIB) milling with ind

We demonstrate manipulating the interactions of a second-order soliton with a weak probe pulse under the condition of group velocity match and group velocity mismatch (GVMM). During these interactions, the second-order soliton act

Lithium-niobate microcavities have not only the ability to resonantly enhance light–matter interaction but also excellent nonlinear optical properties, thereby providing an important platform for nonlinear optical investigations.

Solar-blind ultraviolet photodetectors (SBPDs) have attracted tremendous attention in the environmental, industrial, military, and biological fields. Aluminum gallium nitride (AlGaN), a kind of representative III-nitride semicondu

Fringe projection profilometry (FPP) has been extensively studied in the field of three-dimensional (3D) measurement. Although FPP always uses high-frequency fringes to ensure high measurement accuracy, too many patterns are proje

Ghost imaging (GI) is a technique to retrieve images by correlating intensity fluctuations. In this Letter, we present a novel scheme for GI referred to as second-order cumulants GI (SCGI). The image is retrieved from fluctuation