In this paper, a new type of resonant Brewster filters （RBF） with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning ...In this paper, a new type of resonant Brewster filters （RBF） with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.展开更多
In this paper, a new type of resonant Brewster filter （RBF） consisting of two homogenous layers and a single grating with an equal refractive index is presented. The properties are studied by using the plane wavegui...In this paper, a new type of resonant Brewster filter （RBF） consisting of two homogenous layers and a single grating with an equal refractive index is presented. The properties are studied by using the plane waveguide method （PWM） and rigorous coupled-wave analysis （RCWA）. It is found that the variation of the grating thickness does not effectively change the position of the resonant wavelength, however it has a remarkable effect on the line width, and the resonant peak can be adjusted back to its original position by slightly tuning the grating period. Moreover, by simultaneously tuning the thicknesses of the homogeneous layers above and beneath the grating structure, multiple channels can also be obtained when the RBF is illuminated at the Brewster angle calculated with the effective medium theory （EMT） of subwavelength grating. The adjacent optical thickness for acquiring the multiple channels is about three-quarters of the resonant wavelength. Furthermore, it is demonstrated that the line width at the operating resonant wavelength can be appreciably narrowed by tuning the thickness of the homogenous layer to its corresponding thickness without fine tuning the grating period or the thickness. Therefore, it is very useful for designing filters with different line widths at the desired wavelength. In addition, it is shown from our calculations that the symmetrical line feather can be obtained if the total optical thickness for the homogeneous layer meets the special condition.展开更多
We analytically and numerically study the local dynamical characteristics of the Bessel beams reflected from an airglass interface near the Brewster angle.A Taylor series expansion based on the angular spectrum compon...We analytically and numerically study the local dynamical characteristics of the Bessel beams reflected from an airglass interface near the Brewster angle.A Taylor series expansion based on the angular spectrum component is applied to correct the reflection coefficients near the Brewster angle.Using a hybrid angular spectrum representation and vector potential method,the explicit expressions for the electric and magnetic field components of the reflected Bessel beams are derived analytically under paraxial approximation.The local energy,momentum,spin,and orbital angular momentum of the Bessel beams upon reflection near the Brewster angle are examined numerically by utilizing a canonical approach.Numerical simulation results show that the properties of these dynamical quantities for the Bessel beams near Brewster angle incidence change abruptly,and are significantly affected by their topological charge,half-cone angle,and polarization state.The present study has its importance in understanding the dynamical aspects of optical beams with vortex structure and diffraction-free nature during the reflection process.展开更多
It is an extensively used method recently to prepare the mixed monolayer of cyanine dye by spreading a mixed solution of short chain cyanine dye and long chain fatty acid on a water surface. The method is very importa...It is an extensively used method recently to prepare the mixed monolayer of cyanine dye by spreading a mixed solution of short chain cyanine dye and long chain fatty acid on a water surface. The method is very important for the molecular architecture because it makes non-amphiphilic molecules form monolayer on water surface. But the molecular arrangement of this kind of mixed monolayer is unclear under different surface pressures.展开更多
We report a high repetition frequency, high power stability and low laser noise laser-diode(LD) end-pumped Nd: YAG ceramic passively Q-switched laser at 1123 nm based on a Ti_(3)C_(2)T_(x)-polyvinyl alcohol(PVA) film ...We report a high repetition frequency, high power stability and low laser noise laser-diode(LD) end-pumped Nd: YAG ceramic passively Q-switched laser at 1123 nm based on a Ti_(3)C_(2)T_(x)-polyvinyl alcohol(PVA) film as a saturable absorber(SA). A Brewster polarizer(BP) and a birefringent crystal(BC) are incorporated to enable frequency selection and filtering for the passively Q-switched 1123 nm pulsed laser to improve the power stability and reduce the noise. When the pump power is 5.1 W, an average output power of 457.9 m W is obtained, corresponding to a repetition frequency of 1.09 MHz,a pulse width of 56 ns, a spectral line width of 0.65 nm, a power instability of ±0.92%, and a laser noise of 0.89%.The successful implementation of the “Ti_(3)C_(2)T_(x)-PVA film passively Q-switching” combined with “frequency selection and filtering of BP + BC” technology path provides a valuable reference for developing pulsed laser with high repetition frequency, high stability and low noise.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10704079)
文摘In this paper, a new type of resonant Brewster filters （RBF） with surface relief structure for the multiple channels is first presented by using the rigorous coupled-wave analysis and the S-matrix method. By tuning the depth of homogeneous layer which is under the surface relief structure, the multiple channels phenomenon is obtained. Long range, extremely low sidebands and multiple channels are found when the RBF with surface relief structure is illuminated with Transverse Magnetic incident polarization light near the Brewster angle calculated with the effective media theory of sub wavelength grating. Moreover, the wavelengths of RBF with surface relief structure can be easily shifted by changing the depth of homogeneous layer while its optical properties such as low sideband reflection and narrow band are not spoiled when the depth is changed. Furthermore, the variation of the grating thickness does not effectively change the resonant wavelength of RBF, but have a remarkable effect on its line width, which is very useful for designing such filters with different line widths at desired wavelength.
基金Project supported by the Natural Science Foundation of Shanghai Committee of Science and Technology,China (Grant No. 10ZR1433500)
文摘In this paper, a new type of resonant Brewster filter （RBF） consisting of two homogenous layers and a single grating with an equal refractive index is presented. The properties are studied by using the plane waveguide method （PWM） and rigorous coupled-wave analysis （RCWA）. It is found that the variation of the grating thickness does not effectively change the position of the resonant wavelength, however it has a remarkable effect on the line width, and the resonant peak can be adjusted back to its original position by slightly tuning the grating period. Moreover, by simultaneously tuning the thicknesses of the homogeneous layers above and beneath the grating structure, multiple channels can also be obtained when the RBF is illuminated at the Brewster angle calculated with the effective medium theory （EMT） of subwavelength grating. The adjacent optical thickness for acquiring the multiple channels is about three-quarters of the resonant wavelength. Furthermore, it is demonstrated that the line width at the operating resonant wavelength can be appreciably narrowed by tuning the thickness of the homogenous layer to its corresponding thickness without fine tuning the grating period or the thickness. Therefore, it is very useful for designing filters with different line widths at the desired wavelength. In addition, it is shown from our calculations that the symmetrical line feather can be obtained if the total optical thickness for the homogeneous layer meets the special condition.
基金Project supported by the Natural Science Foundation of Shaanxi Province,China(Grant No.2020JM-210)the National Natural Science Foundation of China(Grant No.61675159).
文摘We analytically and numerically study the local dynamical characteristics of the Bessel beams reflected from an airglass interface near the Brewster angle.A Taylor series expansion based on the angular spectrum component is applied to correct the reflection coefficients near the Brewster angle.Using a hybrid angular spectrum representation and vector potential method,the explicit expressions for the electric and magnetic field components of the reflected Bessel beams are derived analytically under paraxial approximation.The local energy,momentum,spin,and orbital angular momentum of the Bessel beams upon reflection near the Brewster angle are examined numerically by utilizing a canonical approach.Numerical simulation results show that the properties of these dynamical quantities for the Bessel beams near Brewster angle incidence change abruptly,and are significantly affected by their topological charge,half-cone angle,and polarization state.The present study has its importance in understanding the dynamical aspects of optical beams with vortex structure and diffraction-free nature during the reflection process.
文摘It is an extensively used method recently to prepare the mixed monolayer of cyanine dye by spreading a mixed solution of short chain cyanine dye and long chain fatty acid on a water surface. The method is very important for the molecular architecture because it makes non-amphiphilic molecules form monolayer on water surface. But the molecular arrangement of this kind of mixed monolayer is unclear under different surface pressures.
基金Project supported by the Serving Local Special Project of Shaanxi Provincial Department of Education of China (Grant No. 19JC040)the National Natural Science Foundation of China (Grant No. 61905193)。
文摘We report a high repetition frequency, high power stability and low laser noise laser-diode(LD) end-pumped Nd: YAG ceramic passively Q-switched laser at 1123 nm based on a Ti_(3)C_(2)T_(x)-polyvinyl alcohol(PVA) film as a saturable absorber(SA). A Brewster polarizer(BP) and a birefringent crystal(BC) are incorporated to enable frequency selection and filtering for the passively Q-switched 1123 nm pulsed laser to improve the power stability and reduce the noise. When the pump power is 5.1 W, an average output power of 457.9 m W is obtained, corresponding to a repetition frequency of 1.09 MHz,a pulse width of 56 ns, a spectral line width of 0.65 nm, a power instability of ±0.92%, and a laser noise of 0.89%.The successful implementation of the “Ti_(3)C_(2)T_(x)-PVA film passively Q-switching” combined with “frequency selection and filtering of BP + BC” technology path provides a valuable reference for developing pulsed laser with high repetition frequency, high stability and low noise.
