A phase-shift fiber Bragg grating (FBG) with sampling is proposed to generate a multi-channel bandpass filter in the background of multi-channel stopbands. The sampled moire fiber gratings are analyzed by Fourier transform theory

A math model that can describe the effect of stimulated Raman scattering (SRS) on pilot-tone detection technique is proposed. Through numerical simulation, it is shown that the effect of SRS could produce ghost-tones. The power of

Considering spectrum tilt due to signal-to-signal Raman scattering (SSRS) in backward distributed fiber Raman amplifiers (B-DFRA), an inverse tilted on-off gain profile is adopted to achieve flat net gain. A simple approximate lin

We present a method to optimize the flat-band long-period fiber Bragg grating (FBG) in this letter. The method is based on the particle swarm optimization method and the matrix transmission method. The optimized refractive modulat

A high-birefringence linearly chirped fiber Bragg grating (FBG) is written into a polarization-maintaining photosensitive fiber by ultraviolet (UV) beam through a linearly chirped phase mask. Its performance as group velocity disp

Imaging laser radar can give intensity and range images, which provide integrated 3-dimensional (3D) information about objects. However, dropouts and range anomalies exacerbate range images, which makes their background cluttered

A method of image edge detection using the Hopfield neural network (HNN) is proposed in this paper. The image edge parameters are introduced in detail, and the energy function of HNN is given based on the edge parameters. Tests on

We demonstrated a stable single-frequency, single-polarization operation of ytterbium-doped fiber laser. As a novel practical method to realize single-polarization operation of fiber distributed Bragg reflector (DBR) laser, we pro

An improved butt coupling method is used to fabricate an electroabsorption modulator (EAM) monolithically integrated with a distributed feedback (DFB) laser. The obtained electroabsorption-modulated laser (EML) chip with the tradi

Er^(3+)-doped fluoride lanthanum aluminosilicate glasses with compositions of (65-x/2)SiO_(2).(25-x/2)Al~~(2)O~~(3).xAlF~~(3).9.1La~~(2)O~~(3).0.6Er~~(2)O~~(3).0.3Yb~~(2)O~~(3) (x = 4, 8, 12, 20, 30) (mol%) were prepared and thei

Ag-MgF_(2) composite films with different Ag fractions were prepared through a co-evaporation method. Microstructure analysis shows that the films are composed of amorphous MgF~~(2) matrix and embedded fcc-Ag nanoparticles. The o

A novel method to generate a collimated hollow-laser-beam (HLB) by only a single axicon is proposed. With some reasonable assumptions, the radial light intensity distribution is calculated in detail by diffraction integral theory.

We show how a non-local quantum controlled-NOT (CNOT) gate with multiple targets can be implemented with unit fidelity and unit probability. The explicit quantum circuit for implementing the operation is presented. Two schemes for

We start from the intensity distribution of a standing wave (SW) laser field and deduce the classical equation of atomic motion. The image distortion is analyzed using transfer function approach. Atomic flux density distribution a

In order to improve the resolution of seismic acquisition, a new seismic acquisition system based on tangential laser Doppler effect with an optimized differential optical configuration is proposed. The relative movement of the in

Semiconductor fiber temperature sensors have been used widely in many fields, but most of them pick up temperature by measuring the optical intensity of certain fixed narrow-band in absorption spectrum. Furthermore, they are sensi

The spectral changes of a partially coherent polychromatic light focused by an apertured lens with chromatic aberration are investigated. It is demonstrated that the spectrum in the focused field is different from that in the aper

The mechanism of near infrared (IR) focused femtosecond (fs) laser induced defects in silica glasses produced by different methods is systematically investigated through measurements of absorption, fluorescence, and electronic spi

Based on the principle that a rectangular function can be expanded into a sum of complex Gaussian functions with finite numbers, propagation characteristics of a Gaussian beam or a plane wave passing through apertured fractional F