Showing papers on "Supercontinuum published in 2000"
TL;DR: In this article, the authors demonstrate experimentally that air-silica microstructure optical fibers can exhibit anomalous dispersion at visible wavelengths, and exploit this feature to generate an optical continuum 550 THz in width, extending from the violet to the infrared.
Abstract: We demonstrate experimentally for what is to our knowledge the first time that air–silica microstructure optical fibers can exhibit anomalous dispersion at visible wavelengths. We exploit this feature to generate an optical continuum 550 THz in width, extending from the violet to the infrared, by propagating pulses of 100-fs duration and kilowatt peak powers through a microstructure fiber near the zero-dispersion wavelength.
2,372 citations
TL;DR: In this paper, a supercontinuum light with a spectrum more than two octaves broad (370-1545 nm at the 20-dB level) was generated in a standard telecommunications fiber by femtosecond pulses from an unamplified Ti:sapphire laser.
Abstract: Supercontinuum light with a spectrum more than two octaves broad (370–1545 nm at the 20-dB level) was generated in a standard telecommunications fiber by femtosecond pulses from an unamplified Ti:sapphire laser. The fiber had been tapered to a diameter of ∼2 µm over a 90-mm length. The pulse energy was 3.9 nJ (average power, 300 mW). This source of high-intensity single-mode white light should find widespread applications in frequency metrology and spectroscopy, especially since no unconventional fibers are needed.
711 citations
TL;DR: More than 1000 optical frequency channels were generated with 12.5 GHz spacing from a single supercontinuum source in this article, and 600-700 channels for the wavelength range 1512-1580 nm were confirmed to offer SNRs and Q factors sufficient for multi-span 2.5 Gbit/s DWDM transmission.
Abstract: More than 1000 optical frequency channels are generated with 12.5 GHz spacing from a single supercontinuum source. 600–700 channels for the wavelength range 1512–1580 nm are confirmed to offer SNRs and Q factors sufficient for multi-span 2.5 Gbit/s DWDM transmission.
202 citations
TL;DR: In this article, the output of a mode-locked laser is spectrally broadened through supercontinuum generation, which is then encoded into fast wavelength-hopped time-spread waveforms through a wavelength-selective time-delay device.
Abstract: We demonstrate a new technique for implementation of fast wavelength-hopping incoherent optical code-division multiple-access (CDMA). The output pulse from a mode locked laser is spectrally broadened through supercontinuum generation. This then encoded into fast wavelength-hopped time-spread waveforms through a wavelength-selective time-delay device. At the receiver, matched-filter decoding is used to recover data. We present a 1-Gb/s digital transmission experiment through a 15-km dispersion-shifted (DS) single-mode fiber link. This technique avoids the need for a fast wavelength tunable optical source.
83 citations
TL;DR: Direct generation of <500-fs pulses at a 1-GHz rate from a self-starting passively mode-locked fiber laser by regeneratively synchronizing the pulses with a phase modulator is reported.
Abstract: We report direct generation of <500‐fs pulses at a 1-GHz rate from a self-starting passively mode-locked fiber laser by regeneratively synchronizing the pulses with a phase modulator. The pulses are amplified and passed through a dispersion-decreasing fiber and a normal-dispersion supercontinuum fiber. The resulting continuum is wider than 350 nm.
81 citations
TL;DR: In this paper, the authors demonstrate a high-power, multi-wavelength, short pulse source at 10 Gb/s based on spectral slicing of supercontinuum (SC) generated in short fibers.
Abstract: We demonstrate a high-power, multi-wavelength, short pulse source at 10 Gb/s based on spectral slicing of supercontinuum (SC) generated in short fibers. We show that short fiber SC can be used for dense wavelength division multiplexing applications because of its >7.9 dBm/nm power spectral density, 140 nm spectral bandwidth, and /spl plusmn/0.5 dB spectral uniformity over 40 mn. Pulse carving up to 60 nm away from the pump wavelength and CW generation by longitudinal mode carving indicates that the coherence of the SC is maintained. By using high nonlinearity fibers, the spectral bandwidth is increased to 250 nm, which can accommodate >600 wavelength channels with 50 GHz channel spacing and >6 Tb/s aggregate data rate. We also calculate the coherence degradation due to amplification of incoherent energy during the SC generation. Theoretical results show that the SC generation in short fibers has 13 dB higher signal-to-noise ratio (SNR) compared to the SC generated in long fiber.
71 citations
TL;DR: In this paper, the Brillouin/Raman fiber laser (BRFL) was used for CW supercontinuum centered at 1483.4 nm and weak 0.11 nm spectral modulation were observed.
Abstract: About 100 nm CW supercontinuum centered at 1483.4 nm was generated from Brillouin/Raman fiber laser (BRFL). The BRFL consists of a Raman cavity with 700 m of phosphosilicate fiber (PDF) and pairs of fiber Bragg grating (FBG) mirrors and a Brillouin cavity with the PDF, 500 m of flexcor-1060 fiber, and output FBG mirrors. With 8.4 W/1064 nm Yb-doped double-clad fiber laser as pump and 50% feedback FBG mirror at end of BRFL, output power of over 1 W with 100 nm bandwidth centered at 1483.4 nm and weak 0.11 nm spectral modulation were observed.
48 citations
TL;DR: In this paper, it was shown that the supercontinuum generation efficiency decreases as the incident laser polarization changes from linear to circular and thus, provides the first experimental demonstration of the suppression of SG with circularly polarized light.
40 citations
TL;DR: In this paper, a technique for generating 2.5 Gbit/s time spread/wavelength hop (t-spread/spl lambda/-hop) optical codes was developed, based on the use of chirped fibre Bragg gratings (FBG) with a supercontinuum (SC) light source.
Abstract: A technique for generating 2.5 Gbit/s time-spread/wavelength-hop (t-spread//spl lambda/-hop) optical codes. Each with chips at a different wavelength, has been developed, based on the use of chirped fibre Bragg gratings (FBG) with a supercontinuum (SC) light source. 2-channel/spl times/2.5 Gbit/s t-spread//spl lambda/-hop optical code division multiplexing (OCDM) transmission has been demonstrated, and is expounded in detail. Experimental results are compared with numerical results. The limitations of the realisable code are discussed.
39 citations
07 Mar 2000
TL;DR: In this article, the authors investigate supercontinuum generation in normal dispersion fiber in order to assess the feasibility of WDM transmitters based on SC sources and demonstrate that seed pulse shape influences both SC spectrum flatness and its noise characteristics.
Abstract: We investigate supercontinuum generation (SC) in normal dispersion fiber in order to assess the feasibility of WDM transmitters based on SC sources. The interest of this case lies in its relative simplicity, and in the high coherence of the SC spectrum that is obtained through this process. We demonstrate that seed pulse shape influences both SC spectrum flatness and its noise characteristics. Simple design rules for the maximum spectrum magnification and for the corresponding fiber length are proposed. We show numerically and experimentally that a proper design can keep the amplitude noise of the SC spectrum comparable with the amplitude noise of the seed pulse.
33 citations
TL;DR: In this article, the authors report error-free transmission over 544 km of standard fibre of 40 channels at 9.953 Gbit/s from a spectrum-sliced supercontinuum source.
Abstract: The authors report error-free transmission over 544 km of standard fibre of 40 channels at 9.953 Gbit/s from a spectrum-sliced supercontinuum source. All but three of the transmitted channels have error floors better than 10-16.
TL;DR: In this paper, a time-resolved Raman spectroscopy was used to measure stimulated Raman scattering in photoinduced transient species using a Raman pump pulse with narrow bandwidth and a femtosecond supercontinuum probe pulse.
Journal Article•
TL;DR: In this article, the propagation of femtosecond laser pulses in holey fibers is experimentally investigated and it is demonstrated that the use of such fibers allows the efficiency of spectral broadening of femTosecond pulses to be considerably increased as compared with conventional fibers.
Abstract: The propagation of femtosecond laser pulses in holey fibers is experimentally investigated. It is demonstrated that the use of such fibers allows the efficiency of spectral broadening of femtosecond pulses to be considerably increased as compared with conventional fibers.
TL;DR: In this paper, a 40-channel X 9.953 Gbit/s DWDM transmitter based on spectrum-slicing of supercontinuum light generated from an electroabsorption-modulated laser (EML) is described.
Abstract: We describe a 40-channel X 9.953 Gbit/s dense wavelength-division multiplexed (DWDM) transmitter based on spectrum-slicing of supercontinuum light generated from an electroabsorption-modulated laser (EML). Error-free transmission of all channels over 544 km of standard fiber is demonstrated.
07 May 2000
TL;DR: In this paper, the authors have observed ultra-broad supercontinuum generation in a conventional telecommunications optical fiber (cutoff wavelength ~1250 nm, NA = 0.1).
Abstract: Summary form only given. We have observed ultra-broad supercontinuum generation in a conventional telecommunications optical fibre (cutoff wavelength ~1250 nm, NA = 0.1). The fibre was tapered (heated and stretched in a flame) to reduce its diameter to 1.8 μm uniformly over a 90 mm length, without significant loss. Pulses (200-500 fs) from a Ti:sapphire laser tuned to 850 nm were launched into the fibre. The output spectrum for a pulse energy of 3.2nJ, corresponding to 240 mW average power, is plotted. Our tapered fibres (mounted in simple dustproof housings) were robust, surviving several days without degradation. We therefore anticipate that tapered fibres will be effective hosts for a number of other nonlinear effects also.
TL;DR: In this paper, the authors proposed a method for converting optical time division multiplexed (OTDM) signals to WDM signals by using supercontinuum (SC), followed by spectrum slicing and time-gating OC-192 (9953 Gbit/s) OTDM signals.
Abstract: The authors propose a novel method for converting optical time division multiplexed (OTDM) signals to wavelength division multiplexed signals (WDM) by using supercontinuum (SC), followed by spectrum slicing and time-gating OC-192 (9953 Gbit/s) OTDM signals to 4/spl times/OC-48 (2488 Gbit/s) WDM signals conversion with a BER of under 10/sup -9/ is experimentally demonstrated
07 May 2000
TL;DR: In this article, the authors demonstrate a broadband supercontinuum (SC) source with broad flat region (40 nm), high power spectral density (7.9 dBm/nm), high coherence and potentially high temporal resolution.
Abstract: Summary form only given. We demonstrate a broadband (140 nm) supercontinuum (SC) source that has broad flat region (40 nm), high-power spectral density (7.9 dBm/nm), high coherence and potentially high temporal resolution. Compared with other sources used in analog-to-digital (A/D) conversion, short fiber SC simultaneously has quadrupled uniform spectral width, nearly doubled bandwidth and eight times better temporal resolution (/spl sim/5 ps). Based on the parameters of our SC source, we estimate that sampling of continuous signals with <10% pulse-to-pulse variation and up to 400 GSa/s with 1-nm filter spacing is achievable.
07 Mar 2000
TL;DR: In this article, a 150+ channel ultra-DWDM source utilizing longitudinal mode slicing of a 140 nm supercontinuum was reported, and the modes of source laser were replicated in 48 nm region with /spl plusmn/0.5 dB uniformity, precise N/spl times/10 GHz spacing and <7 dB/Hz RIN degradation.
Abstract: We report a 150+ channel ultra-DWDM source utilizing longitudinal mode slicing of a 140 nm supercontinuum. The modes of source laser are replicated in 48 nm region with /spl plusmn/0.5 dB uniformity, precise N/spl times/10 GHz spacing and <7 dB/Hz RIN degradation.
TL;DR: In this article, a comb-like dispersion-profiled fiber (CDPF) was used to compress the 10 GHz, 12 ps pulses generated from an actively mode-locked Er3+ doped fiber ring laser.
Abstract: We built a pulse compressor using a comb-like dispersion-profiled fiber (CDPF). The CDPF consists of 12-segment fibers with the dispersion alternatively high and low. Using this compressor and a 17 dBm Erbium-doped fiber amplifier, the 10 GHz, 12 ps pulses generated from an actively mode-locked Er3+ doped fiber ring laser was compressed to ~ 2 ps without pedestal. We also show that compared with the high order soliton pulse compressor, the power efficiency can be doubled in supercontinuum generation by using the pump pulses compressed by this CDPF compressor.
01 Jan 2000
07 Mar 2000
TL;DR: In this article, the error-free transmission over 544 km of standard fiber of 40 channels at 9.953 Gb/s from a spectrum-sliced supercontinuum source was reported.
Abstract: We report the error-free transmission over 544 km of standard fiber of 40 channels at 9.953 Gb/s from a spectrum-sliced supercontinuum source. All but three of the transmitted channels have error floors better than log(BER)=/spl sim/16.
Journal Article•
TL;DR: In this paper, the supercontinuum created during the propagation of a femtosecond Ti-sapphire laser pulses in matter and especially in air is analyzed. And the authors show that the spectral coherence of the initial laser pulse and the resulting chirped-white-light laser together form a chirping-white light laser.
Abstract: We present some results concerning the propagation of intense femtosecond Ti:sapphire laser pulses in matter and especially in air. We show that the supercontinuum created during the propagation preserves the spectral coherence of the initial pulse and both together form a chirped-white-light laser. Furthermore, we detected the photoemission of N 2 and N 2 + to measure the intensity dependence of a focused laser pulse in air along the propagation distance and we observed a multiple refocusing. Finally, we underlined a clear charge separation in the plasma created a focused pulse in air giving rise to a short electric pulse.
TL;DR: In this article, a focused intense femtosecond Ti: sapphire laser was used for supercontinuum generation in atmospheric-pressure nitrogen by a focused Ti-coated laser at various pulse durations and energies.
Abstract: Supercontinuum generation in atmospheric-pressure nitrogen by a focused intense femtosecond Ti: sapphire laser was studied at various pulse durations and energies. The generated supercontinuum was greatly blue-broadened due to self-phase modulation in the plasma produced. The measured blue-broadening Δω is proportional to pulse intensity for fixed pulse duration, and values up to 0.7ω (ω being the original laser frequency) was obtained with a pulse energy of 9.5 mJ and minimum duration of 100 fs.
TL;DR: In this paper, the dynamics of differential transmission and reflectance spectra of porous silicon films were studied using femtosecond excitation technique (τ≈50 fs, ℏωpump=2.34 eV) with supercontinuum probing (ℏϵprobe=1.6-3.2 eV).
Abstract: The dynamics of differential transmission and reflectance spectra of porous silicon films was studied using the femtosecond excitation technique (τ≈50 fs, ℏωpump=2.34 eV) with supercontinuum probing (ℏωprobe=1.6–3.2 eV) and controlled time delay with a step of Δt=7 fs between the pump and probe pulses. A short-lived region of photoinduced bleaching was observed in the differential transmission spectra at wavelengths shorter than the pump wavelength. The excitation of coherent phonon states with a spectrum corresponding to nanocrystalline silicon with an admixture of a disordered phase was observed. The relaxation of electronic excitation was found to slow down in the spectral region where the amplitude of excited coherent vibrations was maximal.
TL;DR: In this article, the dispersion curve of a Cr: YAG laser rod used for femtosecond pulse generation was measured using an interferometric set-up using a broadband supercontinuum fiber laser.
TL;DR: In this article, the spectral overlap between two adjacent WDM channels is estimated for a typical 10-Gb/s system having 50 GHz of channel spacing, for -20 dB overlap, the product of number of fiber spans and optical power per channel must be less than 18.1 and 15.5 dBm, respectively.
Abstract: Cross-phase modulation induced spectral broadening in WDM systems is measured using a high-resolution optical spectrum analyzer. The measured spectra are consistent with recently developed theoretical models. Using the theoretical models, the spectral overlap between two adjacent WDM channels is estimated for a typical 10-Gb/s system having 50 GHz of channel spacing. For -20 dB overlap, the product of number of fiber spans and optical power per channel must be less than 18.1 and 15.5 dBm for standard and nonzero-dispersion-shifted fiber, respectively.
Proceedings Article•
12 May 2000TL;DR: In this paper, a 10-Hz Ti:sapphire chirped-pulse amplification laser system was used for supercontinuum generation in 1-atm nitrogen and oxygen respectively.
Abstract: Summary form only given. The largest blue-shift in air under a focused intense laser beam has attracted much attention. We report the supercontinuum generation in 1-atm nitrogen and oxygen respectively. The experiments were carried out with a 10-Hz Ti:sapphire chirped-pulse amplification laser system. It delivered pulses of 10 mJ maximum energy and wavelength centered at 805 nm. In the experiments, the laser pulses were focused with a lens (f=11 cm) into a cell which was filled with 1-atm nitrogen or oxygen; the ionization was checked by a pair of electrodes with applied 36 V DC voltage. The transmitted laser radiation was recollimated with a fused-silica lens and sent into a spectrometer coupled with a charge-coupled device camera with a resolution of 0.327 nm. The detection of the spectral component was time integrated, and the results were analyzed with a linked personal computer.
TL;DR: In this article, the characteristics of supercontinuum generation in the dispersion-shifted-fiber are studied both in theory and experiment, and the experimental results agree well with the theoretical simulations.
Abstract: Some characteristics of supercontinuum generation in the dispersion-shifted-fiber are studied both in theory and experiment. The theoretical research shows how the fiber nonlinearities, such as self-phase-modulation, four-wave-mixing and cross-phase-modulation, play their roles in the supercontinuum generation. Some dependent parameters of supercontinuum generation, such as the fiber length, the pump power are also discussed in this paper. The experimental results agree well with the theoretical simulations.
07 May 2000
TL;DR: In this article, a 40-channel 400 Gbit/s SC-DWDM transmitter where seed pulses are obtained from an electroabsorption-modulated DFB laser (EML) is presented.
Abstract: Summary form only given. Dense wavelength-division multiplexed (DWDM) transmitters based on spectrum-slicing of supercontinuum (SC) light have attracted renewed interest recently. So far, all transmission experiments with SC-DWDM sources have used actively mode-locked lasers to seed the supercontinuum, raising concerns about the stability and the practicality of these systems. Picosecond seed pulses can however also be obtained from a DFB laser using a variety of techniques. In this paper, we describe for an example a 40-channel 400 Gbit/s SC-DWDM transmitter where seed pulses are obtained from an electroabsorption-modulated DFB laser (EML). We demonstrate the error-free transmission of all channels over 7 spans (544 km) of standard single-mode fiber. To our knowledge, this is the first system experiment using a mode-locked-laser-free SC-DWDM transmitter.
10 Sep 2000
TL;DR: In this article, the amplitude stability of spectrum-sliced supercontinuum (SC) sources at 1.5 /spl mu/m is investigated. And an amplitude stable 40 ch /spl times/10 Gb/s SC source for DWDM applications is presented.
Abstract: Summary form only given. Supercontinuum (SC) generation is a very attractive way to generate broad spectra. In particular spectrum-sliced SC sources at 1.5 /spl mu/m are of potential interest for dense-wavelength-division-multiplexing systems (DWDM) and networks. In this technique an ultrashort pulse seed generates broad coherent spectra by use of the nonlinear effect in an optical fibre. In this paper we report on experimental and theoretical investigation on amplitude stability of SC spectra. We also present and discuss an amplitude stable 40 ch /spl times/10 Gb/s spectrum-sliced SC source for DWDM applications.