The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a （AB）^N （D）^2 （BA）^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain fac...The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a （AB）^N （D）^2 （BA）^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain factor of the phase-conjugate wave is derived when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode. Because of stronger resonance enhancement to incident pump beam given by the Bragg microcavity, the enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium inside Bragg microcavity is more outstanding than that caused by the naked third order nonlinear optical medium. The theoretical analysis and the numerical calculation show the Bragg microcavity with larger number N of periods is identical with a Fabry-Perot cavity when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode.展开更多
The phase information of an extended source is reconstructed by use of a two-zone （annular） phaseonly filter in a coherent confocel scanning optical microscope. The dependence of its resolution on its source size is...The phase information of an extended source is reconstructed by use of a two-zone （annular） phaseonly filter in a coherent confocel scanning optical microscope. The dependence of its resolution on its source size is investigated theoretically by its three-dimensional optical transfer function （3D OTF）. The results show that the resolution is improved, even though the source size is enlarged.展开更多
A tunable microwave photonic bandpass filter with high mainlobe-to-sidelobe ratio (MSR) based on a phase modulator and a dispersive device is proposed. The multi-tap characteristics of the filter are realized by slici...A tunable microwave photonic bandpass filter with high mainlobe-to-sidelobe ratio (MSR) based on a phase modulator and a dispersive device is proposed. The multi-tap characteristics of the filter are realized by slicing a broadband source using a Mach-Zehnder interferometer (MZI) which results in a high MSR of 25 dB. The tunability of the filter is realized by an optical variable delay line (OVDL) in one arm of the MZI, which changes the wavelength spacing of the sliced broadband source and results in a tunable free spectrum range (FSR) of the filter. The central frequency of the bandpass filter is tunable from 10.7 GHz to 27 GHz by changing the wavelength spacing from 0.145 nm to 0.054 nm.展开更多
文摘The enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium in a （AB）^N （D）^2 （BA）^N Bragg microcavity made of one-dimensional photonic crystals is studied. The gain factor of the phase-conjugate wave is derived when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode. Because of stronger resonance enhancement to incident pump beam given by the Bragg microcavity, the enhancement effect of the phase-conjugate wave produced by a third order nonlinear optical medium inside Bragg microcavity is more outstanding than that caused by the naked third order nonlinear optical medium. The theoretical analysis and the numerical calculation show the Bragg microcavity with larger number N of periods is identical with a Fabry-Perot cavity when the resonance condition is satisfied by the incident optical wave and the Bragg microcavity mode.
文摘The phase information of an extended source is reconstructed by use of a two-zone （annular） phaseonly filter in a coherent confocel scanning optical microscope. The dependence of its resolution on its source size is investigated theoretically by its three-dimensional optical transfer function （3D OTF）. The results show that the resolution is improved, even though the source size is enlarged.
基金supported by the National Natural Science Foundation of China (No.60808004)the New Century Excellent Talents in University (No.NCET-07-0611)the Tianjin Natural Science Foundation (No.08JCYBJC14500)
文摘A tunable microwave photonic bandpass filter with high mainlobe-to-sidelobe ratio (MSR) based on a phase modulator and a dispersive device is proposed. The multi-tap characteristics of the filter are realized by slicing a broadband source using a Mach-Zehnder interferometer (MZI) which results in a high MSR of 25 dB. The tunability of the filter is realized by an optical variable delay line (OVDL) in one arm of the MZI, which changes the wavelength spacing of the sliced broadband source and results in a tunable free spectrum range (FSR) of the filter. The central frequency of the bandpass filter is tunable from 10.7 GHz to 27 GHz by changing the wavelength spacing from 0.145 nm to 0.054 nm.
