Based on the transfer matrix method, a detailed theoretical and numerical study on double-phase-shifted fiber Bragg grating (FBG) is investigated. Temporal responses of the double-phase-shifted FBG to optical pulse are analyzed and the influence of the tw
Bi-doped SiO2–Al2O3–GeO2 fiber preforms are prepared by modified chemical vapor deposition (MCVD) and solution doping process. The characteristic spectra of the preforms and fibers are experimentally investigated, and a distinct difference in emission bet
A novel wavelet denoising (WD) assisted wavelength modulation technique is proposed for improving near-infrared detection performance on methane concentration based on tunable diode laser absorption spectroscopy (TDLAS). Due to the ability of multi-level
The intracavity photon density is assumed to be of Gaussian spatial distributions and its longitudinal variation is also considered in the rate equations for a laser diode (LD) end-pumped passively Q-switched Nd:YVO4 laser with GaAs saturable absorber. Th