We report the first experimental observation of nonlinear propagation effects in fiber Bragg gratings, resulting optical pulse compression and soliton propagation. The solitons occur at frequencies near photonic band gap grating; they are due to a combination negative dispersion grating, which dominates material dispersion, self-phase modulation. propagate velocities well below speed light uniform medium.

A 40mm long optical fibre grating superstructure is written by translating an ultraviolet writing beam along a and phase-mask assembly while its intensity periodically varied. The reflects at multiple wavelengths, equally spaced 0.13 nm, over range of more than 1.0 nm. This structure has applications in signal processing tunable lasers.

Chirped sampled fibre Bragg gratings have a dispersion that repeats itself periodically, and can thus be used for compensation over broad bandwidth, or multiple channels in WDM systems. The authors demonstrate at two different wavelengths with such grating 240 km link using 10 Gbit/s externally modulated laser source.

A novel in-fiber structure for power-referenced refractometry with the capability to measure surrounding refractive index (SRI) as low 1.33 is proposed and demonstrated.A short optical fiber stub containing a weakly tilted Bragg grating spliced another large lateral offset.The reflection from this occurs in two well-defined wavelength bands, reflected core mode cladding modes.The modes reflect different amounts of power SRI changes, while core-mode same FBG remains unaffected by SRI.The band...

The authors present a new method for realising continuously tunable reflectively tapped optical transversal filter processor. This is based on the use of long chirped fibre Bragg gratings as tapping elements. A notch demonstrated with decade tuning range, highest reported to date.

Silica planar waveguide echelle grating demultiplexers with 48 channels and 256 are described demonstrated. Polarization effects due to stress birefringence polarization-dependent efficiency have been eliminated using a modified polarization compensator design. The devices wavelength shift of less than 10 pm, loss below 0.2 dB. 48-channel device has measured crosstalk -35 dB, an insertion better 4 uniformity 1 dB across the C-band.

We demonstrate a compact power-referenced fiber-optic accelerometer using weakly tilted fiber Bragg grating (TFBG) combined with an abrupt biconical taper.The electric-arc-heating induced taper is located short distance upstream from the TFBG and functions as bridge to recouple TFBG-excited lower-order cladding modes back into core.This recoupling extremely sensitive microbending.We avoid complex wavelength interrogation by simply monitoring power change in reflection, which we show be...

A ${\mathrm{D}}_{2}$O far-infrared laser emitting 0.5J in 1.4 \ensuremath{\mu}s at 385 \ensuremath{\mu}m and a heterodyne receiver system comprising Schottky barrier diode mixer with noise temperature of 8000\ifmmode^\circ\else\textdegree\fi{} K (double sideband) were used Thomson scattering experiment to measure the ion tokamak plasma during single shot. Series measurements under reproducible conditions have been carried out hydrogen, deuterium, helium plasmas. Their statistical analysis...

We demonstrate a compact, passive temperature-compensating package for fiber gratings. The grating is mounted under tension in comprising two materials with different thermal-expansion coefficients. As the temperature rises strain progressively released, compensating dependence of Bragg wavelength. A 50 mm long and 5 diameter exhibited total variation wavelength 0.07 nm over 100 °C range, compared 0.92 an uncompensated grating.

We analyze a fiber Bragg grating by focusing the beam of probe laser (λ = 633 nm) through side onto its core. Designed for retroreflection at some longer wavelength (λB 1290 nm), causes reflection if input angle is chosen suitably. The reflected power proportional to square amplitude refractive-index modulation probed position. By scanning along we measure axial profile with spatial resolution 10 μm. measured consistent single-photon UV writing process.

Dispersion compensation is demonstrated experimentally by pulse compression with the use of chirped optical fiber Bragg gratings. The gratings chirp self-induced Gaussian intensity profile 240-nm wavelength beam used for holographic sidewriting grating. Chirped pulses generated a 1.55-microm gain-switched distributed-feedback laser an initial duration 21 ps and spectral width 0.7 nm are compressed to 13 ps, in good agreement theory.

We report the observation of an optical Wannier-Stark ladder in a linearly chirped Moir\'e grating, written core fiber. The use photons avoids strong excitonic interactions encountered more traditional experiments using charge carriers semiconductors.

Dispersion compensation using a fibre Bragg grating in transmission is reported. The authors demonstrate at 10 Gbit/s over 72 km of non-dispersion shifted with no power penalty an 11 cm long unchirped, tapered strength. Using 106 non-dispersion. fibre, there 2 dB penalty.

We briefly review our recent nonlinear propagation experiments in optical fiber Bragg gratings (FBGs). These demonstrate pulse compression, and shaping, also show how a train of pulses may be generated from single input pulse. Our results the existence grating solitons, solitons which exist by balancing nonlinearity glass dispersion grating.

A 120 mm long fibre Bragg grating, adjustably chirped by an offset-core technique, compensates for dispersion in a 10 Gbit/s optical communication system operating at 1054 µm over 270 km of non-dispersion-shifted fibre. Simultaneous compensation and source chirp directly modulated is also described.

We report the observation of fluorescence at 530 to 550 nm from erbium-doped germanosilicate fiber under strong pumping in 980-nm band. The observed nonlinear dependence on pump power is shown arise a sequential two-photon absorption ground state (4)F(7/2) through short-lived (4)I(11/2) intermediate state. Rate-equation modeling shows that this excited-state influenced by population cycling induced amplified spontaneous emission metastable (4)I(13/2)

ABSTRACT Spray‐formed hypereutectic aluminium silicon alloy DISPAL® S232–T6x is cycled with variable amplitude at ultrasonic frequency up to the very high cycle fatigue (VHCF) regime under fully reversed tension–compression loading. The Powder Metallurgy tested using a Gaussian cumulative distribution of load cycles, and lifetimes are compared constant data. Miner calculation delivers mean damage sums between 0.5 0.9 for 8 × 10 7 1.6 respectively. Cracks initiated voids, inclusions or...

This paper reports a novel architecture for the design of dense wavelength-division multiplexing interleavers based on planar echelle gratings. Double astigmatic point grating is discussed. The important and inherent limitation aberrations associated with has been eliminated by introduction aberration free elliptical facets. A mechanism compensating variations refractive index wavelength also described. theoretical analysis was used to manufacture remarkably low footprint 50/100 100/200 GHz...

Arrays of both annular and square slots in a conducting sheet on dielectric substrate have been fabricated photolithographically. The structures are shown to behave as bandpass filters the far infrared, with resonant wavelength slightly larger than average circumference or perimeter slot. measured far-infrared transmittance array is approximately 76% that predicted by theory, while its frequency agrees theory within 5%.

A chirped, 12-cm-long fiber Bragg grating with 10-nm spectral bandwidth was employed in place of a conventional diffraction pair compressor compact fiber-based high-energy chirped-pulse-amplification system. Initial nanosecond chirped pulses from fast-tuned laser diode were compressed to produce 1.9-ps-long, 300-nJ pulses.

A new approach for eliminating aberration effects through introduction of elliptical grating facets in optical comb filters is presented. Simulation results show remarkable improvements filter performance aberration-free compared to traditional flat facet designs. The proposed theory was validated design and fabrication 100-GHz-period planar silica-on-silicon use multiwavelength sources. Multimode interference structures were used achieve both flat-top Gaussian spectral responses. All...