When the film is excited by a very low excitation energy, thespontaneous Raman scattering emerges. The intensity of Ramanscattering is proportional to the Excitation power below thethreshold excitation. When the excit...When the film is excited by a very low excitation energy, thespontaneous Raman scattering emerges. The intensity of Ramanscattering is proportional to the Excitation power below thethreshold excitation. When the excited power reaches the Excitationthreshold, the intensity of Stokes light strongly increases.Meanwhile an anti- Stokes light at 495 nm and multiple order butsmall Stokes peaks occur. The intensity of Stokes light is muchlarger than that of anti-Stokes.展开更多
The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fl...The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.展开更多
The La2/3Cal/3Mn03_σ film has been deposited on the （001） SrTiO3 substrate and its temper- ature-dependent photoconductive properties have been investigated from 80 to 300 K. The La2/3Cal/3MnO3-σ film has a novel ...The La2/3Cal/3Mn03_σ film has been deposited on the （001） SrTiO3 substrate and its temper- ature-dependent photoconductive properties have been investigated from 80 to 300 K. The La2/3Cal/3MnO3-σ film has a novel photoelectric property due to its oxygen-deficient structure. We observed laser-induced giant negative photoresistance of the sample in a wide temperature range. The change rate of negative photoresistance was nearly 100% at the low temperature when the sample was irradiated by 532 nm laser. In addition, this effect was sensitive to the power of laser irradiation. The oxygen-deficiency of La2/3Cal/3Mn03-σ film seems to have an impact on the laser-induced resistance variation. The experimental results made the La2/3Cal/3MnO3_σ film a promising application as a photoswitch device.展开更多
The performance of broadband polarizing beam splitters(PBSs) is sensitive to the incident angle.By taking account of the spectrum of the laser source and using the needle optimization method,a large acceptance angle P...The performance of broadband polarizing beam splitters(PBSs) is sensitive to the incident angle.By taking account of the spectrum of the laser source and using the needle optimization method,a large acceptance angle PBS for laser-based displays is designed.The average degrees of polarization in transmission and reflection can reach 0.989 and 0.980 for an acceptance angle of 13.6?in air using two materials,while better results of 0.993 and 0.989 for an acceptance angle of 14.8?in air are attained when three common materials are used.Both designs consist of 40 layers.展开更多
We propose a vertical cavity semiconductor emitting laser(VCSEL)using a coupled-cavity(CC)design to broaden the bandwidths of gain and delay spectra.The structure is formed by constructing a passive cavity coupled wit...We propose a vertical cavity semiconductor emitting laser(VCSEL)using a coupled-cavity(CC)design to broaden the bandwidths of gain and delay spectra.The structure is formed by constructing a passive cavity coupled with the active cavity.By rendering the strength of the two resonant cavities,the increased gain bandwidth by 340%and the increased delay bandwidth by 800%are achieved as compared with the signal-cavity(SC)VCSEL.The wideband spectra present more square-like passband which is expected for slow light system.By using it,a 20 Gbit/s super Gaussian signal is delayed by about 13 ps with high quality.展开更多
文摘When the film is excited by a very low excitation energy, thespontaneous Raman scattering emerges. The intensity of Ramanscattering is proportional to the Excitation power below thethreshold excitation. When the excited power reaches the Excitationthreshold, the intensity of Stokes light strongly increases.Meanwhile an anti- Stokes light at 495 nm and multiple order butsmall Stokes peaks occur. The intensity of Stokes light is muchlarger than that of anti-Stokes.
基金Project(50101007) supported by the National Science Natural Foundation of China
文摘The physical characteristics and microstructure of the fluoride film formed during activation were investigated using SEM,XPS and SAM,and its stability in electroless nickel(EN) bath was analyzed.The effects of the fluoride film on EN deposition were studied additionally.The results show that the fluoride film on magnesium alloys is a kind of porous film composed of MgF2 with thickness of 1.6-3.2 μm.The composition of the activation bath and pretreatment of EN processing have influence on the composition of the fluoride film.The fluoride is stable and dissolves little in EN bath;as a result,the fluoride film can protect magnesium substrate from the corrosion of EN bath.The composition of fluoride determines the initial deposition of EN and part of the fluoride film finally exists as inclusion in EN coating.
基金supported by National Basic Research Program of China(973 Program)(Grant No.2014CB7443-02)Specially Founded Program on National Key Scientific Instruments and Equipment Development(Grant No.2012YQ140005)
文摘The La2/3Cal/3Mn03_σ film has been deposited on the （001） SrTiO3 substrate and its temper- ature-dependent photoconductive properties have been investigated from 80 to 300 K. The La2/3Cal/3MnO3-σ film has a novel photoelectric property due to its oxygen-deficient structure. We observed laser-induced giant negative photoresistance of the sample in a wide temperature range. The change rate of negative photoresistance was nearly 100% at the low temperature when the sample was irradiated by 532 nm laser. In addition, this effect was sensitive to the power of laser irradiation. The oxygen-deficiency of La2/3Cal/3Mn03-σ film seems to have an impact on the laser-induced resistance variation. The experimental results made the La2/3Cal/3MnO3_σ film a promising application as a photoswitch device.
基金supported by the National Natural Science Foundation of China (No.50802080)the Natural Science Foundation of Fujian Province (No.2010J01349)
文摘The performance of broadband polarizing beam splitters(PBSs) is sensitive to the incident angle.By taking account of the spectrum of the laser source and using the needle optimization method,a large acceptance angle PBS for laser-based displays is designed.The average degrees of polarization in transmission and reflection can reach 0.989 and 0.980 for an acceptance angle of 13.6?in air using two materials,while better results of 0.993 and 0.989 for an acceptance angle of 14.8?in air are attained when three common materials are used.Both designs consist of 40 layers.
基金supported by the National Basic Research Program of China(No.2012CB315704)the National Natural Science Foundation of China(No.61101053)
文摘We propose a vertical cavity semiconductor emitting laser(VCSEL)using a coupled-cavity(CC)design to broaden the bandwidths of gain and delay spectra.The structure is formed by constructing a passive cavity coupled with the active cavity.By rendering the strength of the two resonant cavities,the increased gain bandwidth by 340%and the increased delay bandwidth by 800%are achieved as compared with the signal-cavity(SC)VCSEL.The wideband spectra present more square-like passband which is expected for slow light system.By using it,a 20 Gbit/s super Gaussian signal is delayed by about 13 ps with high quality.
