We investigate the multilevel modulation for red-green-blue light emitting diode (RGB LED). A simple approach for extracting soft values from the modulation is proposed. The mapping way from bits to the modulated symbols for the m

We investigate the on-line writing identical fiber Bragg grating (FBG) arrays using the phase mask technique. Given the limitation of laser power, the energy density uniformity and the horizontal width of the writing spot cannot b

We propose a new phase-modulation-combination system for the generation of arbitrarily shaped repetition rate pulses. In this system, the pulses from two electro-optic switches are modulated and interferentially combined, thereby

This letter proposes a scheme for the format conversion of on-off keying (OOK) signal to quadrature phase-shift keying (QPSK) and 16-ary quadrature amplitude modulation (16QAM) signals via cross-phase modulation (XPM) in a semicon

We propose and experimentally demonstrate a photonic approach to estimate the time-difference-of-arrival (TDOA) and the angle-of-arrival (AOA) of a microwave signal. TDOA and AOA are estimated from the carrier power difference of

The provision of quintuple-play services along wavelength division multiplexed (WDM) long-reach passive optical networks (LR-PONs) employing an ultra-bendable fiber in last-mile distribution is demonstrated experimentally. Particu

An ultra-compact variable optical attenuator based on slow light photonic crystal waveguide with thermooptic effect is demonstrated. Along with power consumption of as low as 30.7 mW, a variable attenuation range of 10 dB is exper

An improved method for stabilizing a frequency-quadrupled 214.5-nm tunable diode laser system is reported. Improvements to the method include a homemade logic circuit and the use of a Fabry-Perot optical spectrum analyzer as a tra

We study nanometer copper thin films prepared by magnetron sputtering and treated with laser shock processing (LSP). We observe the formation of firstborn twin crystals and some complete twin crystals in the copper thin films. Aft

A wireless terahertz digital transmission link is demonstrated, in which a quantum-cascade laser and a spectrally-matched quantum-well photodetector serve as the emitter and receiver, respectively. An on-off modulation scheme is u

High-strained InGaAs/InGaAsP multiple quantum wells (MQWs) distributed feedback (DFB) lasers, fabricated using metal organic chemical vapor deposition, are presented at 1.82 \mu m with a high side-mode-suppression ratio of 49.53 d

We describe a Q-switched Er:GdVO4 laser resonantly pumped by a MgO-doped periodically poled LiNbO3 optical parametric oscillator (MgO: PPLN OPO) at 1 536 nm. In continuous-wave lasing, the maximum output power is 1.14 Wwith an inc

The domain wall regions in periodically poled MgO-doped LiNbO3 (PPMgLN) crystal are examined by using second harmonic generation (SHG). The results show that the average domain walls that separate the individual domains have a wid

Stripe motion artifacts caused by phase fluctuation in phase-resolved optical coherence tomography (OCT) result in the quality degradation of the image ofin vivo blood flow of human eye. In order to suppress the stripe motion arti

This letter shows that the human eye fundus tissue has higher reflectivity at the near-infrared (NIR) wavelength, and that some aberrations exist at the pre-optical system from cornea to vitreous. We design a NIR fundus camera wit

A unified theory to construct exact optical rogue wave solutions of (1+1)-dimensional nonlinear Schrodinger equation with varying coefficients is proposed. The dynamics of the first-order optical rogue waves in nonlinear graded-in

An echelle diffraction grating based high-resolution spectrometer-on-chip on silicon oxynitride (SiON) waveguide platform operated at a wavelength range of 850 nm is demonstrated. The chip comprises 120 output waveguides with 0.25

A systematic series of silicon (Si) wafer with microstructured anti-reflection film is prepared by femtosecond laser pulse. The dependence of the morphology and optical properties of the microstructured Si on the experimental para

High contrast transparent Ramsey fringes are observed using double microwave pulses interaction with the prepared atomic coherent state in a warm 87Rb vapor with mixture buffer gases in a closed cell. The Ramsey fringes are genera

Accommodation and convergence play critical roles in the natural viewing of three-dimensional (3D) scenes, and these must be accurately matched to avoid visual fatigue. However, conventional stereoscopic head-mounted displays lack

Freeform optical surfaces (FOSs) will be the best elements in the design of compact optical systems in the future. However, it is extremely difficult to measure freeform surface with sufficient accuracy, which impedes the developm

K-shell X-ray emission from a Cu nanowire target irradiated by an ultraintense femtosecond laser pulse is studied using an elliptically bent quartz crystal and imaging plate. The designed bent crystal spectrometer has better spect

We experimentally demonstrate the generation of an array of optical bottle beams by employing multiple self-accelerating Airy beams. This kind of optical bottle array is created by superimposing eight Airy beams along a circle, al