Laser-diode pumped Q-switched ytterbium-doped switching time of acousto-optic modulator （AOM） fiber laser is studied experimentally by controlling the The characteristics of Q-switched pulses with different rise tim...Laser-diode pumped Q-switched ytterbium-doped switching time of acousto-optic modulator （AOM） fiber laser is studied experimentally by controlling the The characteristics of Q-switched pulses with different rise time of AOM regulated by the laser beam size along the window of AOM are presented. Meanwhile, the behaviors of Q-switched pulses are achieved by regulating the switching time of AOM. The singlerepetition-rate and half-repetition-rate phenomena are described and discussed. The experimental results confirm that the fiber laser with lower level inversion population can be more easily operated for half- repetition-rate generation.展开更多
This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polyprop...This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polypropylene coated with silica oxide (BOPP-SiOx) by an inkjet printer.Compared to the conventional chrome-mask,it is of advantages such as suitable for non-planar substrates,scalable for large area production,and extreme low cost.Combined with the confined photo-catalytic oxidation (CPO) reaction,the printed flexible BOPP-SiOx photomask was successfully used to pattern the shape of wettability of organic polymer surfaces,and then polyaniline patterns were deposited on the modified substrates with strong adhesion.With the above photomasks,the polyacrylic acid graft chains were duplicated on the poly (ethylene terephthalate) (PET) and BOPP substrates by photografting polymerization.We grafted polyacrylic acid (PAA) on a non-planar plastic substrate with this soft and thin plastic photomask.Scanning electron microscopy (SEM) and optical microscopy were used to characterize the surface morphology and thickness of ink layers of the printed photomask.Optical microscopy was used to characterize the deposition polyaniline micropatterns.It was found that the desired patterns were precisely printed on the modified polymer films and were applied in modifying organic polymer substrates.The printed photomask could be exploited in the fields such as prototype microfluidics,micro-sensors,optical structures and any other kind of microstructures which does not require high durability and dimensional stability.展开更多
Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microsco...Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microscopy (CD-AFM). In the measurements, the contribution of its AFM tip geometry is usually the dominant error source, as measured AFM images are the dilated results of measured structures by the AFM tip geometry. To solve this problem, a bottom-up approach has been applied in calibrating the (effective) AFM tip geometry where the result is traceably calibrated to the lattice constant of silicon crystals. The other is transmission electron microscopy (TEM). For achieving measurement traceability, structure features are measured in pairs in TEM images;thus the distance between the structure pair calibrated by a metrological AFM in prior can be applied to determine the magnification of the TEM image. In this study, selected photomask structures are calibrated by the CD-AFM, and then sample prepared and measured by high-resolution TEM nearly at the same location. The results are then compared. Of six feature groups compared, the results agree well within the measurement uncertainty, indicating excellent performance of the developed methodology. This research supports the development of a photomask standard, which is applied as a “reference ruler” with improved low measurement uncertainty in photomask fabs.展开更多
基金supported by the National Key Basic Research Project of China
文摘Laser-diode pumped Q-switched ytterbium-doped switching time of acousto-optic modulator （AOM） fiber laser is studied experimentally by controlling the The characteristics of Q-switched pulses with different rise time of AOM regulated by the laser beam size along the window of AOM are presented. Meanwhile, the behaviors of Q-switched pulses are achieved by regulating the switching time of AOM. The singlerepetition-rate and half-repetition-rate phenomena are described and discussed. The experimental results confirm that the fiber laser with lower level inversion population can be more easily operated for half- repetition-rate generation.
基金supports from the Changjiang Scholars and Innovative Research Team in University (IRT 0706)Program of Introducing Talents of Discipline to Universities (B08003) are greatly appreciated
文摘This article presents a simple,fast and low-cost method to fabricate a flexible UV light photomask.The designed micropatterns were directly printed onto transparent hybrid composite film of biaxially oriented polypropylene coated with silica oxide (BOPP-SiOx) by an inkjet printer.Compared to the conventional chrome-mask,it is of advantages such as suitable for non-planar substrates,scalable for large area production,and extreme low cost.Combined with the confined photo-catalytic oxidation (CPO) reaction,the printed flexible BOPP-SiOx photomask was successfully used to pattern the shape of wettability of organic polymer surfaces,and then polyaniline patterns were deposited on the modified substrates with strong adhesion.With the above photomasks,the polyacrylic acid graft chains were duplicated on the poly (ethylene terephthalate) (PET) and BOPP substrates by photografting polymerization.We grafted polyacrylic acid (PAA) on a non-planar plastic substrate with this soft and thin plastic photomask.Scanning electron microscopy (SEM) and optical microscopy were used to characterize the surface morphology and thickness of ink layers of the printed photomask.Optical microscopy was used to characterize the deposition polyaniline micropatterns.It was found that the desired patterns were precisely printed on the modified polymer films and were applied in modifying organic polymer substrates.The printed photomask could be exploited in the fields such as prototype microfluidics,micro-sensors,optical structures and any other kind of microstructures which does not require high durability and dimensional stability.
基金Open Access funding enabled and organized by Projekt DEAL.
文摘Accurate metrology of extreme ultraviolet (EUV) photomask is a crucial task. In this paper, two different methods for reference EUV photomask metrology are compared. One is the critical dimension atomic force microscopy (CD-AFM). In the measurements, the contribution of its AFM tip geometry is usually the dominant error source, as measured AFM images are the dilated results of measured structures by the AFM tip geometry. To solve this problem, a bottom-up approach has been applied in calibrating the (effective) AFM tip geometry where the result is traceably calibrated to the lattice constant of silicon crystals. The other is transmission electron microscopy (TEM). For achieving measurement traceability, structure features are measured in pairs in TEM images;thus the distance between the structure pair calibrated by a metrological AFM in prior can be applied to determine the magnification of the TEM image. In this study, selected photomask structures are calibrated by the CD-AFM, and then sample prepared and measured by high-resolution TEM nearly at the same location. The results are then compared. Of six feature groups compared, the results agree well within the measurement uncertainty, indicating excellent performance of the developed methodology. This research supports the development of a photomask standard, which is applied as a “reference ruler” with improved low measurement uncertainty in photomask fabs.
