The purpose is to study modules of double crossproducts D (X, A) of Skew-Hopf pairs ( X, A). A sufficient and necessary condition for M to be D ( X, A)-mod is shown. Relations between D ( X, A)-mod and quantam Yang-Ba...The purpose is to study modules of double crossproducts D (X, A) of Skew-Hopf pairs ( X, A). A sufficient and necessary condition for M to be D ( X, A)-mod is shown. Relations between D ( X, A)-mod and quantam Yang-Baxter A-mod or X-mod are revealed.展开更多
We report optimal phase modulation based on enhanced electro–optic effects in a Mach–Zehnder（MZ） modulator constructed by AlGaAs/GaAs coupled double quantum well（CDQW） waveguides with optical gain. The net chang...We report optimal phase modulation based on enhanced electro–optic effects in a Mach–Zehnder（MZ） modulator constructed by AlGaAs/GaAs coupled double quantum well（CDQW） waveguides with optical gain. The net change of refractive indexes between two arms of the CDQW MZ modulator is derived by both the electronic polarization method and the normal-surface method. The numerical results show that very large refractive index change over 10^（-1） can be obtained, making the phase modulation in the CDQW MZ modulator very highly efficient. It is desirable and important that a very small voltage-length product for π phase shift, V_π× L_0= 0.0226 V · mm, is obtained by optimizing bias electric field and CDQW structural parameters, which is about seven times smaller than that in single quantum-well MZ modulators.These properties open an avenue for CDQW nanostructures in device applications such as electro–optical switches and phase modulators.展开更多
A quantum cascade laser（QCL） based system for simultaneous detection of CO and CO_2 is developed.The QCL can scan over two neighboring CO（2055.40 cm^（-1）） and CO_2（2055.16 cm^（-1）） lines with a single curren...A quantum cascade laser（QCL） based system for simultaneous detection of CO and CO_2 is developed.The QCL can scan over two neighboring CO（2055.40 cm^（-1）） and CO_2（2055.16 cm^（-1）） lines with a single current scan.The wavelength modulation spectroscopy（ f = 20 k Hz） is utilized to enhance the signal-to-noise ratio.A white cell with an effective optical path length of 74 m is used.The calibration of the sensor is performed and minimum detection limits of 1.3 ppb（1 × 10^（-9））for CO and 0.44 ppm（1 × 10^（-6）） for CO_2 are achieved.展开更多
Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-sig...Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-signal modulation characteristics of the simultaneous ground-state （GS） and the excited-state （ES） lasing in InAs/OaAs quantum dot laser diodes. The large-signal modulation capability of total light intensity in the transition regime from OS lasing to two-state lasing is unchanged as the bias-current increases. However, GS and ES large-signal eye diagrams show obvious variations during the transition. Relaxation oscillations and large-signal eye diagrams for OS, ES, and total light intensities are numerically simulated and analyzed in detail by using a rate-equation model. The -ndings show that a complementary relationship between the light intensities for OS and ES lasing exists in both the transition regime and the two-state lasing regime, leading to a much smaller overshooting power and a shorter settling time for the total light intensity. Therefore, the eye diagrams of GS or ES lasing are diffuse whereas those of total light intensity are constant as the bias-current increases in the transition regime.展开更多
We propose a new scheme on modulating the lasing performance of a quantum dot-cavity system. Compared to the conventional above-band pump, in our new scheme an additional resonant driving field is applied on the quant...We propose a new scheme on modulating the lasing performance of a quantum dot-cavity system. Compared to the conventional above-band pump, in our new scheme an additional resonant driving field is applied on the quantum dot-cavity system. By employing the master equation theory and the Jaynes-Cummings model, we are able to study the interesting phenomenon of the coupling system. To compare the different behaviors between using our new scheme and the conventional method,we carry out investigatioin for both the 'good system'and 'more realistic system', characterizing several important parameters, such as the cavity population, exciton population and the second-order correlation function at zero time delay. Through numerical simulations,we demonstrate that for both the good system and more realistic system, their lasing regimes can be displaced into other regimes in the presence of a resonant driving field.展开更多
This paper gives a sufficient and necessary condition for a bialgebra to be a Long bialgebra, and proves a braided product to be a Long bialgebra under some conditions. It also gives a direct sum decomposition of quan...This paper gives a sufficient and necessary condition for a bialgebra to be a Long bialgebra, and proves a braided product to be a Long bialgebra under some conditions. It also gives a direct sum decomposition of quantum Yang-Baxter modules over Long bialgebras.展开更多
In this paper, we mainly construct quantization of dimodule algebras and quantum Yang-Baxter H-module algebras, and give some results of smash products and braided products.
We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and select...We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and selective area epitaxy steps that are essential in traditional fabrication methods.The source integrates an array of distributed feedback(DFB)lasers with a passive coupler and semiconductor optical amplifier(SOA).Ridge waveguide lasers with sampled Bragg side wall gratings have been integrated using quantum well intermixing to achieve a fully functional four-channel DWDM source with 0.8 nm wavelength spacing and residual errors<0.13 nm.The output power from the SOA is>10 mW per channel making the source suitable for use in passive optical networks(PONs).We have also investigated using multisection phase-shifted sampled gratings to both increase the effective grating coupling coefficient and precisely control the channel lasing wavelength spacing.An 8-channel DFB laser array with 100 GHz channel spacing was demonstrated using a sampled grating with twoπ-phase-shifted sections in each sampling period.The entire array was fabricated by only a single step of electron beam lithography.展开更多
As a continuation of the work of Beattie on quantum groups constructed byOre extensions, in this paper, we characterize their centre and discuss the category ofquantum Yang-Baxter modules over them. In addition, we de...As a continuation of the work of Beattie on quantum groups constructed byOre extensions, in this paper, we characterize their centre and discuss the category ofquantum Yang-Baxter modules over them. In addition, we determine all finite dimen-sional irreducible representations over these quantum groups.展开更多
Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication p...Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication processes are described and compared.展开更多
文摘The purpose is to study modules of double crossproducts D (X, A) of Skew-Hopf pairs ( X, A). A sufficient and necessary condition for M to be D ( X, A)-mod is shown. Relations between D ( X, A)-mod and quantam Yang-Baxter A-mod or X-mod are revealed.
基金Project supported by the National Natural Science Foundation of China(Grant No.11474106)the Natural Science Foundation of Guangdong Province,China(Grant No.2016A030313439)the Science and Technology Program of Guangzhou City,China(Grant No.201707010403)
文摘We report optimal phase modulation based on enhanced electro–optic effects in a Mach–Zehnder（MZ） modulator constructed by AlGaAs/GaAs coupled double quantum well（CDQW） waveguides with optical gain. The net change of refractive indexes between two arms of the CDQW MZ modulator is derived by both the electronic polarization method and the normal-surface method. The numerical results show that very large refractive index change over 10^（-1） can be obtained, making the phase modulation in the CDQW MZ modulator very highly efficient. It is desirable and important that a very small voltage-length product for π phase shift, V_π× L_0= 0.0226 V · mm, is obtained by optimizing bias electric field and CDQW structural parameters, which is about seven times smaller than that in single quantum-well MZ modulators.These properties open an avenue for CDQW nanostructures in device applications such as electro–optical switches and phase modulators.
基金Project supported by the National Key Scientific Instrument and Equipment Development Project of China(Grnat No.2014YQ060537)the National Basic Research Program of China(Grant No.2013CB632803)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA05040102)the National Natural Science Foundation of China(Grant No.41405134)
文摘A quantum cascade laser（QCL） based system for simultaneous detection of CO and CO_2 is developed.The QCL can scan over two neighboring CO（2055.40 cm^（-1）） and CO_2（2055.16 cm^（-1）） lines with a single current scan.The wavelength modulation spectroscopy（ f = 20 k Hz） is utilized to enhance the signal-to-noise ratio.A white cell with an effective optical path length of 74 m is used.The calibration of the sensor is performed and minimum detection limits of 1.3 ppb（1 × 10^（-9））for CO and 0.44 ppm（1 × 10^（-6）） for CO_2 are achieved.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFB0402302the National Natural Science Foundation of China under Grant No 91433206
文摘Large-signal modulation capability, as an important performance indicator, is directly related to the high-speed optical communication technology involved. We experimentally and theoretically investigate the large-signal modulation characteristics of the simultaneous ground-state （GS） and the excited-state （ES） lasing in InAs/OaAs quantum dot laser diodes. The large-signal modulation capability of total light intensity in the transition regime from OS lasing to two-state lasing is unchanged as the bias-current increases. However, GS and ES large-signal eye diagrams show obvious variations during the transition. Relaxation oscillations and large-signal eye diagrams for OS, ES, and total light intensities are numerically simulated and analyzed in detail by using a rate-equation model. The -ndings show that a complementary relationship between the light intensities for OS and ES lasing exists in both the transition regime and the two-state lasing regime, leading to a much smaller overshooting power and a shorter settling time for the total light intensity. Therefore, the eye diagrams of GS or ES lasing are diffuse whereas those of total light intensity are constant as the bias-current increases in the transition regime.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274178,61475197 and 61590932the Natural Science Foundation of the Jiangsu Higher Education Institutions under Grant No 15KJA120002+1 种基金the outstanding Youth Project of Jiangsu Province under Grant No BK20150039the Priority Academic Program Development of Jiangsu Higher Education Institutions under Grant No YX002001
文摘We propose a new scheme on modulating the lasing performance of a quantum dot-cavity system. Compared to the conventional above-band pump, in our new scheme an additional resonant driving field is applied on the quantum dot-cavity system. By employing the master equation theory and the Jaynes-Cummings model, we are able to study the interesting phenomenon of the coupling system. To compare the different behaviors between using our new scheme and the conventional method,we carry out investigatioin for both the 'good system'and 'more realistic system', characterizing several important parameters, such as the cavity population, exciton population and the second-order correlation function at zero time delay. Through numerical simulations,we demonstrate that for both the good system and more realistic system, their lasing regimes can be displaced into other regimes in the presence of a resonant driving field.
基金National Natural Science Foundation of P.R.China No.10571153Post-Doctoral Program of P.R.China,No.2005037713+1 种基金Post-Doctoral Program of Jiangsu Province of China No.0203003403National Science Foundation of Jiangsu Province of China
文摘This paper gives a sufficient and necessary condition for a bialgebra to be a Long bialgebra, and proves a braided product to be a Long bialgebra under some conditions. It also gives a direct sum decomposition of quantum Yang-Baxter modules over Long bialgebras.
基金Supported by the Science and Technology Research Key Foundation of the Ministry of Education of China (Grant No.108154)the National Natural Science Foundation of China (Grant No.10871170)
文摘In this paper, we mainly construct quantization of dimodule algebras and quantum Yang-Baxter H-module algebras, and give some results of smash products and braided products.
基金This work was supported by the U.K.Engineering and Physical Sciences Research Council(EP/R042578/1)and the National Science Foundation of China(61320106013).We would like to acknowledge the staff of the James Watt Nanofabrication Centre at the University of Glasgow for help in fabricatingthe devices.
文摘We report a low-cost manufacturing approach for fabricating monolithic multi-wavelength sources for dense wavelength division multiplexing(DWDM)systems that offers high yield and eliminates crystal regrowth and selective area epitaxy steps that are essential in traditional fabrication methods.The source integrates an array of distributed feedback(DFB)lasers with a passive coupler and semiconductor optical amplifier(SOA).Ridge waveguide lasers with sampled Bragg side wall gratings have been integrated using quantum well intermixing to achieve a fully functional four-channel DWDM source with 0.8 nm wavelength spacing and residual errors<0.13 nm.The output power from the SOA is>10 mW per channel making the source suitable for use in passive optical networks(PONs).We have also investigated using multisection phase-shifted sampled gratings to both increase the effective grating coupling coefficient and precisely control the channel lasing wavelength spacing.An 8-channel DFB laser array with 100 GHz channel spacing was demonstrated using a sampled grating with twoπ-phase-shifted sections in each sampling period.The entire array was fabricated by only a single step of electron beam lithography.
基金Supported by the National Natural Science Foundation of Chinaa(10071078)andthe Young Teacher's Projects from the Chinese Education Ministry.
文摘As a continuation of the work of Beattie on quantum groups constructed byOre extensions, in this paper, we characterize their centre and discuss the category ofquantum Yang-Baxter modules over them. In addition, we determine all finite dimen-sional irreducible representations over these quantum groups.
文摘Multiple quantum well spatial light modulators with 128×128 array in 38μm pitch are fabricated using two pproaches, one with an attachment of an optical substrate and another one without. These two fabrication processes are described and compared.
