Harderalbert5376

We experimentally demonstrate tunable optical single-sideband (SSB) generation using a tapped-delay-line (TDL) optical filter for 10 and 20 Gbit/s on/off-keying (OOK) signals and a 20 Gbit/s four-level pulse-amplitude-modulated (PAM4) signal. The optical SSB filter is realized by using an optical frequency comb, wavelength-dependent delay, and nonlinear wave-mixing to achieve the TDL function. Moreover, SSB tunability is achieved by adjusting the amplitude, phase, frequency spacing, and number of selected optical frequency comb lines. We show that the one-sideband suppression of a double-sideband (DSB) channel can be enhanced as the number of taps is increased; however, we do measure a ∼1.5% error-vector-magnitude penalty. Furthermore, we demonstrate that the chromatic-dispersion-induced penalty after 80 km standard-single-mode-fiber transmission of a 10 Gbit/s SSB OOK signal without chromatic dispersion compensation has been reduced by >3dB when compared to DSB.A frequency and intensity noise immune fiber dispersion spectrometer with a digitally enhanced homodyne phase extraction system is presented. A hydrogen cyanide (H13CN) vapor cell is placed in a digitally enhanced Sagnac interferometer, and the anomalous dispersion at the 1550.515 nm P11 transition is interrogated with a tunable laser. An analytical model of the dispersion induced phase readout shows close agreement with the experimentally obtained phase signal. Immunity to frequency and intensity noise confers sub-microradian phase sensitivity, corresponding to a spectroscopic detection limit of 77ppb×m/Hz.We demonstrated a method of fabricating three-dimensional (3D) metal structures in hydrogels with good conductivity by using femtosecond laser ablation and electroplating. The hydrogel containing Ag+ was first ablated by a femtosecond laser to form microchannels with an entrance achieving surface and then sandwiched between the anode and cathode to operate electroplating. Silver structures were formed along the microchannel from the microchannel entrance close to the cathode due to reduction of Ag+. The average resistivity of metal structures is measured to be about 4×10-7Ωm. A tetrahedron metallic microstructure embedded in hydrogel by this method was demonstrated to show its ability of 3D micromachining.We report on faithful reconstruction in polarization holography independent of the exposure time and the reading wave that is suitable for high-speed recording and reconstructing. Faithful reconstruction, the reconstructed wave being identical to the signal wave, is the basis of the application of polarization holography, which may be applied in many fields. Unfortunately, in many cases, faithful reconstruction depends on the exposure time and the reading wave when phenanthrenequinone-doped polymethyl methacrylate is used as the recording material, and then it is not easy to obtain faithful reconstruction. This limits its application in the field of high-speed recording and reconstructing. Directed by the newly developed tensor polarization holography theory, we report on faithful reconstruction breaking through these limitations. In the recording stage, the signal and reference waves are s- and p- polarized, respectively. In the reconstructing stage, the reading wave is arbitrarily polarized. More importantly, the obtained faithful reconstruction has nothing to do with exposure time and it is time saving. The reported faithful reconstruction would bring great convenience and is suitable for high-speed recording and reconstructing.In this Letter, we experimentally demonstrate a 50Gb/s/λ four-level pulse amplitude modulation-based passive optical network system with a 10 G class receiver. A memory polynomial equalizer (MPE) combined with a decision feedback equalizer (DFE) is applied to eliminate channel distortions in the system. To further improve the performance of the MPE-DFE, for the first time, to the best of our knowledge, a low-complexity hybrid decision scheme (HDS) is proposed, which consists of single-symbol decision (SSD) and multi-symbol decision (MSD). The SSD is exactly the conventional hard decision based on minimum Euclidean distance, whereas MSD is based on a simplified maximum likelihood detection principle with M-algorithm. In terms of complexity, MSD requires 19.1% more multiplications than SSD, but the symbol number of MSD only accounts for less than 20% of the total signal frame when the received optical power is greater than -27dBm. Experimental results show that the proposed MPE-DFE with HDS achieves a 0.7 dB and 1.3 dB sensitivity gain compared with conventional SSD, and up to 35.4 dB and 31.4 dB link power budget, regarding the forward error correction threshold of 10-2 and 10-3, respectively.Femtosecond laser-induced modification in the glass has drawn considerable interest due to its widespread superiority in the applications of three-dimensional optical storage. In this Letter, we report that a single pulse could be used in optical memory with super-high writing speed. The photoluminescence image and spectrum indicate that one pulse-induced permanent photoreduction of Sm3+ to Sm2+ in Sm3+-doped sodium aluminoborate glass can be achieved. https://www.selleckchem.com/products/Nafamostat-mesylate.html Consequently, strong emission contrast is obtained, which is used for optical storage. By regulating the fabrication conditions, the fluorescent diameter could be controlled to approximately 800 nm, which demonstrates the feasibility in super-high density optical storage. Besides, multi-layer information is successfully inscribed. The proposed technique of single-pulse writing holds great potential for optical memory with high speed and huge capacity.We show theoretically that anisotropy of the electronic distribution function inside the laser-irradiated metal leads to the formation of edge currents at the timescale of distribution isotropization. When the electronic pressure in the skin layer is anisotropic, the pressure gradient appears to be non-potential force producing a low-frequency magnetic field. In the case of femtosecond laser pumping, the estimated internal magnetic field reaches magnitude up to 1 T even in the non-damaging interaction regime. We demonstrate that this field is localized inside the metal, while just a minor part of its energy is radiated into free space as a sub-terahertz signal.