The red edge position (REP) has been widely used to estimate vegetation parameters and also as a sensitive indicator of vegetation stress. Detailed characterizations of REP can be easily achieved from hyperspectral data obtained from imaging spectrometers. After launch of imaging spectrometers, shift in the center wavelength of the spectral channel may occur due to the vibrations and aging of c...

We report the first demonstration of polarisation insensitive all-optical wavelength conversion (AOWC) for single wavelength channel 640 Gbit/s return-to-zero differential-phase-shift-keying (RZ-DPSK) signal and 1.28 Tbit/s polarisation multiplexed (Pol-Mux) RZ-DPSK signals using a 100-m polarisation-maintaining highly nonlinear fiber (PM-HNLF) in a polarisation diversity loop configuration. Th...

We report the design criteria and performance of Si ring resonators for passive athermal applications in wavelength division multiplexing (WDM). The waveguide design rules address i) positive-negative thermo-optic (TO) composite structures, ii) resonant wavelength dependent geometry to achieve constant confinement factor (Gamma), and iii) observation of small residual second order effects. We d...

We present what is to our knowledge the first demonstration of a tunable fiber Bragg grating device in polymer optical fiber that utilizes a thin-film resistive heater deposited on the surface of the fiber. The polymer fiber was coated via photochemical deposition of a Pd/Cu metallic layer with a procedure induced by vacuum-ultraviolet radiation at room temperature. The resulting device, when w...

Four-wave mixing (FWM) in semiconductor optical amplifiers is an attractive mechanism for wavelength conversion in wavelength-division multiplexed (WDM) systems since it provides modulation format and bit rate transparency over wide tuning ranges. A series of systems experiments evaluating several aspects of the performance of these devices at bit rates of 2.5 and 10 Gb/s are presented. Include...

We demonstrated a continuous-wave (CW) self-Raman laser with high conversion efficiency by using Yb:KGW as the Raman crystal. The first Stokes line of wavelength centered at 1095.2 nm with spectral bandwidth of 8 nm and the cascaded Raman conversion wavelength at 1109.5 nm with spectral bandwidth of 3.4 nm were observed with a Raman shift of 89 cm⁻¹ with respect to the fundamental laser wavelen...

We demonstrate a tunable optical tapped delay line that can simultaneously and independently operate on multiple wavelength-division multiplexed (WDM) data signals. The system utilizes the wavelength-dependent speed of light, together with nonlinear wavelength conversion stages. A phase-preserving scheme enables coherent addition of the weighted taps. We reconfigured the system to perform separ...

this work aims to extract the mineralogical constituents of the lahroud hyperion scene situated in the nw of iran. like the other push-broom sensors, hyperion images suffer from spectral distortions, namely the smile effect. the corresponding spectral curvature is defined as an across-track wavelength shift from the nominal central wavelength, and alters the pixel spectra. the common “column me...

A simple fiber-Bragg-grating (FBG) sensor system based on a linear-cavity fiber laser is proposed and experimentally demonstrated. The lasing wavelength shift resulting from the temperature variation on this sensing element is discriminated by two FBGs. These two FBGs, acting as wavelength discriminators, are used to increase the real-time measurement range for monitoring the temperature variat...

The properties of binary blazed grating were theoretically analyzed with finite-difference time -domain (FDTD) method. The diffraction efficiencies and diffraction angles of –1, 0, and +1 order for the grating varying with wavelength, grating structure, and the etch depth were studied when the incident angle was 30°. The numerical simulations revealed that the binary blazed grating presented hi...