We report on a conceptually new type of waveguide in glass by femtosecond laser direct writing,namely,photonic latticelike waveguide(PLLW).The PLLWfs core consists of well-distributed and densified tracks with a sub-m...We report on a conceptually new type of waveguide in glass by femtosecond laser direct writing,namely,photonic latticelike waveguide(PLLW).The PLLWfs core consists of well-distributed and densified tracks with a sub-micron size of 0.62μm in width.Specifically,a PLLW inscribed as hexagonal-shape input with a ring-shape output side was implemented to converse Gaussian mode to doughnut-like mode,and high conversion efficiency was obtained with a low insertion loss of 1.65 dB at 976 nm.This work provides a new freedom for design and fabrication of the refractive index profile of waveguides with sub-micron resolution and broadens the functionalities and application scenarios of femtosecond laser direct-writing waveguides in future 3D integrated photonic systems.展开更多
In this Letter,we presented a flexible omnidirectional reflective film made of polymer substrates and multiple alternating layers of two chalcogenide glasses for full-angle CO_(2) laser protection.The structure parame...In this Letter,we presented a flexible omnidirectional reflective film made of polymer substrates and multiple alternating layers of two chalcogenide glasses for full-angle CO_(2) laser protection.The structure parameters of the device were simulated for theoretical prediction of best device structure.The reflector was fabricated by alternate thermal evaporation of two chalcogenide glasses with large refractive index contrast.The reflectivity was greater than 78%at 10.6μm.The flexible reflective film can provide an effective solution for full-angle CO_(2) laser protection of the moving targets,such as laser operators and mobile optical components,with potential applications for wearable laser protective clothing.展开更多
Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate （BK7） glass containing Ce^3 ＋ ions under focused infrared femtosecond laser irradiation. The emission spectra show that t...Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate （BK7） glass containing Ce^3 ＋ ions under focused infrared femtosecond laser irradiation. The emission spectra show that the upconversion luminescence comes from the 4f-5d transition of the Ce^3 ＋ ions. The relationship between the intensity of the Ce^3 ＋ emission and the pump power reveals that a three-photon absorption predominates in the conversion process from the near-infrared into the blue luminescence. The analysis of the upconversion mechanism suggests that the upconversion luminescence may come from a three-photon simultaneous absorption that leads to a population of the 5d level in which the characteristic luminescence occurs.展开更多
The femtosecond laser induced void array inside Al2O3 crystals was discussed. The void array was formed spontaneously under the irradiation of a single beam of infrared femtosecond laser which was focused at a fixed p...The femtosecond laser induced void array inside Al2O3 crystals was discussed. The void array was formed spontaneously under the irradiation of a single beam of infrared femtosecond laser which was focused at a fixed point inside the Al2O3 crystal sample. It was found that the regular voids only could be fabricated near the sample surface, which was different from the situation in CaF2 single crystal reported before. The possible mechanism of the phenomena was also discussed.展开更多
基金This work was supported by the National Key R&D Program of China(No.2021YFB2800500)National Natural Science Foundation of China(Nos.U20A20211,51902286,61775192,61905215,51772270,62105297,and 61905093)+1 种基金Zhejiang Provincial Natural Science Foundation(No.LQ22F050022)State Key Laboratory of High Field Laser Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,and Fundamental Research Funds for the Central Universities.
文摘We report on a conceptually new type of waveguide in glass by femtosecond laser direct writing,namely,photonic latticelike waveguide(PLLW).The PLLWfs core consists of well-distributed and densified tracks with a sub-micron size of 0.62μm in width.Specifically,a PLLW inscribed as hexagonal-shape input with a ring-shape output side was implemented to converse Gaussian mode to doughnut-like mode,and high conversion efficiency was obtained with a low insertion loss of 1.65 dB at 976 nm.This work provides a new freedom for design and fabrication of the refractive index profile of waveguides with sub-micron resolution and broadens the functionalities and application scenarios of femtosecond laser direct-writing waveguides in future 3D integrated photonic systems.
基金supported by the National Natural Science Foundation of China(No.61875064)。
文摘In this Letter,we presented a flexible omnidirectional reflective film made of polymer substrates and multiple alternating layers of two chalcogenide glasses for full-angle CO_(2) laser protection.The structure parameters of the device were simulated for theoretical prediction of best device structure.The reflector was fabricated by alternate thermal evaporation of two chalcogenide glasses with large refractive index contrast.The reflectivity was greater than 78%at 10.6μm.The flexible reflective film can provide an effective solution for full-angle CO_(2) laser protection of the moving targets,such as laser operators and mobile optical components,with potential applications for wearable laser protective clothing.
基金Project supported bythe National Natural Science Foundation of China (50125258 and 60377040)
文摘Near-infrared to visible upconversion luminescence was observed in a multicomponent silicate （BK7） glass containing Ce^3 ＋ ions under focused infrared femtosecond laser irradiation. The emission spectra show that the upconversion luminescence comes from the 4f-5d transition of the Ce^3 ＋ ions. The relationship between the intensity of the Ce^3 ＋ emission and the pump power reveals that a three-photon absorption predominates in the conversion process from the near-infrared into the blue luminescence. The analysis of the upconversion mechanism suggests that the upconversion luminescence may come from a three-photon simultaneous absorption that leads to a population of the 5d level in which the characteristic luminescence occurs.
基金the National Natural Science Foundation of China (No.50672087)the National Basic Research Program of China (No.2006CB806000b).
文摘The femtosecond laser induced void array inside Al2O3 crystals was discussed. The void array was formed spontaneously under the irradiation of a single beam of infrared femtosecond laser which was focused at a fixed point inside the Al2O3 crystal sample. It was found that the regular voids only could be fabricated near the sample surface, which was different from the situation in CaF2 single crystal reported before. The possible mechanism of the phenomena was also discussed.
