In theory, we study the quantum tluctuatlons ot tlae suDllarmonlc renecteu nela Irom a ulplc-rc^ulltUtt IdU^ClIClatC optical parametric amplifier （OPA） inside an optical cavity. We discuss two cases, where the linew...In theory, we study the quantum tluctuatlons ot tlae suDllarmonlc renecteu nela Irom a ulplc-rc^ulltUtt IdU^ClIClatC optical parametric amplifier （OPA） inside an optical cavity. We discuss two cases, where the linewidth of the harmonic field is either much narrower or broader than the subharmonic field. Since an electromagnetically-induced-transparency （EIT）-like effect can be simulated in a triple-resonant OPA, the output spectra from a triple-resonant OPA with a squeezed vacuum input may simulate the phenomenon of the response of an EIT medium for squeezed states. This scheme can be implemented with present experimental setups.展开更多
Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy （FNOPAS） is a versatile technique with advantages of high sensitivity, broad detection bandwidth, and intrinsic spec...Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy （FNOPAS） is a versatile technique with advantages of high sensitivity, broad detection bandwidth, and intrinsic spectrum correction func- tion. These advantages should benefit the study of coherent emission, such as measurement oflasing dynamics. In this letter, the FNOPAS was used to trace the lasing process in Rhodamine 6G （R6G） solution and organic semiconductor nano-wires. High-quality transient emission spectra and lasing dynamic traces were acquired, which demonstrates the applicability of FNOPAS in the study of lasing dynamics. Our work extends the application scope of the FNOPAS technique.展开更多
We demonstrate the output characteristic of broadband parametric amplification of incoherent light pulses in a 355-nm pumped degenerate picosecond optical parametric amplification with either saturated or unsaturated ...We demonstrate the output characteristic of broadband parametric amplification of incoherent light pulses in a 355-nm pumped degenerate picosecond optical parametric amplification with either saturated or unsaturated amplification. The optical parametric amplifier is seeded by the fluorescence generated in a solution of pyridine-1 dye in ethanol. With the saturated amplification, we can obtain high energy incoherent light pulses, whose full width at half maximum bandwidth varies from 16 nm to 53 nm for the different phase matching angles near degeneracy. Moreover, the unsaturated bandwidth of the amplified pulses fits well to the calculated result at degeneracy. Selecting s-polarized fluorescence with a Glan-Taylor prism, the maximum bandwidth of the amplified fluorescence is found to be 59 nm for a purely s-polarized seed. The maximum output energy is 0.67 mJ for the optical parametric amplifier. By using an optical filter and compressor, the generated high energy incoherent light has great potential as the incoherent pump, signal or idler wave of a parametric down-conversion process, so that a wave with a high degree of coherence can be generated from an incoherent pump light.展开更多
In this paper, the solution of the time-dependent Fokker-Planck equation of non-degenerate optical parametric amplification is used to deduce the condition demonstrating the Einstein-Podolsky-Rosen （EPR） paradox. Th...In this paper, the solution of the time-dependent Fokker-Planck equation of non-degenerate optical parametric amplification is used to deduce the condition demonstrating the Einstein-Podolsky-Rosen （EPR） paradox. The analytics and numerical calculation show the influence of pump depletion on the error in the measurement of continuous variables. The optimum realization of EPR paradox can be achieved by adjusting the parameter of squeezing. This result is of practical importance when the realistic experimental conditions are taken into consideration .展开更多
A compact two-stage optical parametric chirped pulse amplifier based on photonic crystal fibre is demonstrated. A 1064-nm soliton pulse is obtained in a home-made photonic crystal fibre （PCF） with femtosecond pulse ...A compact two-stage optical parametric chirped pulse amplifier based on photonic crystal fibre is demonstrated. A 1064-nm soliton pulse is obtained in a home-made photonic crystal fibre （PCF） with femtosecond pulse pumping and then amplified to 2 mJ in an Nd：YAG regenerative amplifier. After the amplified pulses pass through the LBO crystal, the 532-nm double-frequency light with an energy of 0.8 mJ and a duration of over 100 ps at 10-Hz repetition rate is generated as a pump source in the following two-stage optical parametric amplification （OPA）. The 850-nm chirped signal light gain from the stretcher is 1.5 × 10^4 in the first-stage OPA while it is 120 in the second-stage OPA. The total signal gain of optical parametric chirped pulse amplification （OPCPA） can reach 1.8 × 10^6.展开更多
This paper applies the minimum variance V1 criterion to monitor the evolution of signal and idler modes of a composite non-degenerate optical parametric amplification （NOPA） system. The analytics and numerical calcu...This paper applies the minimum variance V1 criterion to monitor the evolution of signal and idler modes of a composite non-degenerate optical parametric amplification （NOPA） system. The analytics and numerical calculation show the influence of the transition time, the vacuum fluctuations, and the thermal noise level on the EPR entanglement of the composite NOPA system. It finds that the entanglement and the squeezing degrade as the minimum variance V1 increases.展开更多
Combined with the optical beam deflection,a novel approach of phase matched broadband scanning optical parametric chirped pulse amplification(OPCPA)was proposed.For this scheme,there was no superfluous operations to t...Combined with the optical beam deflection,a novel approach of phase matched broadband scanning optical parametric chirped pulse amplification(OPCPA)was proposed.For this scheme,there was no superfluous operations to the chirped signal pulse which propagated in a changeless direction straightforward,but the pump beam were deflected in space with time by passing through a KTN crystal,which was applied with varied driving voltage.The theories of phase matching of each chirped signal frequency based on pump beam deflection was analyzed detailedly.And the type-I amplification of chirped signal with 800 nm central wavelength and 20 nm bandwidth pumped by 532 nm in BBO crystal was simulated as a case in point.The simulation results showed that the spectral distribution of chirped signal pulse was almost the same as the initial form,i.e.,there was nearly no narrowing on the amplified spectrum by using of the scanning OPCPA based on pump beam deflection.In addition,the simulations demonstrated that it was worth minimizing the voltage deviation applied to KTN crystal as much as possible for the sake of better waveform,larger bandwidth and higher conversion efficiency of amplified signal pulse in the proposed scanning OPCPA.展开更多
Since the proof-of-principle demonstration of optical parametric amplification to efficiently amplify chirped laser pulses in 1992, optical parametric chirped pulse amplification（OPCPA） became the most promising met...Since the proof-of-principle demonstration of optical parametric amplification to efficiently amplify chirped laser pulses in 1992, optical parametric chirped pulse amplification（OPCPA） became the most promising method for the amplification of broadband optical pulses. In the meantime, we are witnessing an exciting progress in the development of powerful and ultrashort pulse laser systems that employ chirped pulse parametric amplifiers. The output power and pulse duration of these systems have ranged from a few gigawatts to hundreds of terawatts with a potential of tens of petawatts power level. Meanwhile, the output pulse duration based on optical parametric amplification has entered the range of fewoptical-cycle field. In this paper, we overview the basic principles, trends in development, and current state of the ultrashort and laser systems based on OPCPA, respectively.展开更多
This paper theoretically studies the double-pumped fibre-optical parametric amplifiers （FOPAs） in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the ...This paper theoretically studies the double-pumped fibre-optical parametric amplifiers （FOPAs） in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed.展开更多
The generation of power-and wavelength-scalable few optical cycle pulses remains one of the major challenges in modern laser physics.Over the past decade,the development of table-top optical parametric chirped pulse a...The generation of power-and wavelength-scalable few optical cycle pulses remains one of the major challenges in modern laser physics.Over the past decade,the development of table-top optical parametric chirped pulse amplificationbased systems was progressing at amazing speed,demonstrating excellent performance characteristics in terms of pulse duration,energy,peak power and repetition rate,which place them at the front line of modern ultrafast laser technology.At present,table-top optical parametric chirped pulse amplifiers comprise a unique class of ultrafast light sources,which currently amplify octave-spanning spectra and produce carrier-envelope phase-stable,few optical cycle pulses with multi-gigawatt to multi-terawatt peak powers and multi-watt average powers,with carrier wavelengths spanning a considerable range of the optical spectrum.This article gives an overview on the state of the art of table-top optical parametric chirped pulse amplifiers,addressing their relevant scientific and technological aspects,and provides a short outlook of practical applications in the growing field of ultrafast science.展开更多
An impedance matched parametric amplifier(IMPA)with Josephson junctions is fabricated and characterized.A hybrid structure containing coplanar and strip structures is implemented to realize an impedance taper line and...An impedance matched parametric amplifier(IMPA)with Josephson junctions is fabricated and characterized.A hybrid structure containing coplanar and strip structures is implemented to realize an impedance taper line and a plate capacitor in an LC nonlinear resonator based on Josephson junctions.The upper plate of the capacitor is isolated with SiNx without grounding as well as the strips.Such easily-prepared designs greatly reduce the requirements for lithography alignment and precision,which makes the fabrication process more reliable.The experimental results show that in such IMPA a gain higher than 25 dB with a bandwidth of about 100 MHz can be obtained.This broadband amplifier operates close to the quantum limit.By adjusting the working point,a higher bandwidth of about 400 MHz can be obtained with a gain of about 17 dB.展开更多
In this paper, an analytical model to investigate the parametric amplification （PA） and the PA ＋ stimulated Raman scattering （SRS） in silicon waveguides is put forward. When two pump signals are employed, the PA ...In this paper, an analytical model to investigate the parametric amplification （PA） and the PA ＋ stimulated Raman scattering （SRS） in silicon waveguides is put forward. When two pump signals are employed, the PA bandwidth of the probe signal is so large that the Raman contribution has to be considered. When Raman contribution fraction f is set to be 0, only the PA occurs to amplify the probe signal, and when f is set to be 0.043, the PA and the SRS amplify the probe signal at the same time. The signal amplifications of both single and dual pump schemes are investigated by using this model. With this model, three main affecting factors, i.e., zero dispersion wavelength （ZDWL）, third-order dispersion （TOD）, and fourth-order dispersion （FOD）, are discussed in detail.展开更多
Surface plasmon polariton（SPP）, a sub-wavelength surface wave promising for photonic integration, always suffers from the large metallic loss that seriously restricts its practical application. Here, we propose a co...Surface plasmon polariton（SPP）, a sub-wavelength surface wave promising for photonic integration, always suffers from the large metallic loss that seriously restricts its practical application. Here, we propose a compact SPP amplifier based on a nonlinear hybrid waveguide（a combination of silver, LiNbO3, and SiO2）, where a couple of Bragg gratings are introduced in the waveguide to construct a cavity. This special waveguide is demonstrated to support a highly localized SPP-like hybrid mode and a low loss waveguide-like hybrid mode. To provide a large nonlinear gain, a pumping wave input from the LiNbO3 waveguide is designed to resonate inside the cavity and satisfy the cavity phase matching to fulfill the optical parametric amplification（OPA） of the SPP signal. Proper periods of gratings and the cavity length are chosen to satisfy the impedance matching condition to ensure the high input efficiency of the pump wave from the outside into the cavity. In theoretical calculations, this device demonstrates a high performance in a very compact scheme（~3.32 μm） and a much lower pumping power for OPA compared with single-pass pumping. To obtain a comprehensive insight into this cavity OPA, the influences of the pumping power, cavity length, and the initial phase are discussed in detail.展开更多
The performances of a dual-pump parametric and Raman amplification process and the wavelength conversion in silicon waveguides are investigated. By setting the Raman contribution fraction f to be 0.043 in our analytic...The performances of a dual-pump parametric and Raman amplification process and the wavelength conversion in silicon waveguides are investigated. By setting the Raman contribution fraction f to be 0.043 in our analytical model, the amplification gain of the probe signal can be obtained to be over 10 dB. The pump transfer noise （PTN）, the quantum noise （QN）, and the total noise figure （TNF） are discussed, and the TNF has a constant value of about 4 dB in the gain bandwidth. An idler signal generated during the parametric amplification （PA） process can be used to realize the wavelength conversion in wavelength division multiplexing （WDM） systems. In addition, the pump signal parameters, the generated free carrier lifetime and effective mode area （EMA） of the waveguide are analysed for the optimization of signal gain and noise characteristics.展开更多
We present an experimental investigation of a filamentation-assisted fourth-order nonlinear optical process in KTP crystals pumped by intense 1.53 eV （807 nm） femtosecond laser pulses. Femtosecond light pulses at 2....We present an experimental investigation of a filamentation-assisted fourth-order nonlinear optical process in KTP crystals pumped by intense 1.53 eV （807 nm） femtosecond laser pulses. Femtosecond light pulses at 2.58 eV （480 nm） are generated by the fourth-order nonlinear polarization （p（4） （ω2） = X（4） （ω2, ω, ω, ω, -ω1）E3 （ω）E＊ （ω1）, where E（w） corresponds to the pump frequency and E（wl） to the supercontinuum generated through filamentation）. If the system is seeded by a laser beam at ω1 or ω2 and there are spatial and temporal overlaps with the pump beam, E（ω1） and E（ω2） are simultaneously amplified. When the intensity of the seed laser beam exceeds a certain intensity threshold, the contribution of p（4） （ω） = X（4） （ω, ω1, ω2, -ω, -ω）E（ω1）E（ω2）（E＊ （ω））2 becomes non-negligible, and the amplification weakens. The conversion efficiency from the pump to the signal at 2.58 eV （480 nm） attains to 0.1%.展开更多
基金supported by the National Basic Research Program of China (Grant No. 2011CB921601)the National Natural Science Foundation of China for Excellent Research Team (Grant No. 61121064)+1 种基金the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20111401130001)the Graduate Outstanding Innovation Item of Shanxi Province, China (Grant No. 20113001)
文摘In theory, we study the quantum tluctuatlons ot tlae suDllarmonlc renecteu nela Irom a ulplc-rc^ulltUtt IdU^ClIClatC optical parametric amplifier （OPA） inside an optical cavity. We discuss two cases, where the linewidth of the harmonic field is either much narrower or broader than the subharmonic field. Since an electromagnetically-induced-transparency （EIT）-like effect can be simulated in a triple-resonant OPA, the output spectra from a triple-resonant OPA with a squeezed vacuum input may simulate the phenomenon of the response of an EIT medium for squeezed states. This scheme can be implemented with present experimental setups.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.20925313 and 21503066)the Innovation Program of Chinese Academy of Sciences(Grant No.KJCX2-YW-W25)+1 种基金the Postdoctoral Project of Hebei University,Chinathe Project of Science and Technology Bureau of Baoding City,China(Grant No.15ZG029)
文摘Femtosecond time-resolved fluorescence non-collinear optical parametric amplification spectroscopy （FNOPAS） is a versatile technique with advantages of high sensitivity, broad detection bandwidth, and intrinsic spectrum correction func- tion. These advantages should benefit the study of coherent emission, such as measurement oflasing dynamics. In this letter, the FNOPAS was used to trace the lasing process in Rhodamine 6G （R6G） solution and organic semiconductor nano-wires. High-quality transient emission spectra and lasing dynamic traces were acquired, which demonstrates the applicability of FNOPAS in the study of lasing dynamics. Our work extends the application scope of the FNOPAS technique.
基金Project supported by the National Basic Research Program of China (Grant No. 2007CB613205)the National Natural Science Foundation of China (Grant No. 61078005)
文摘We demonstrate the output characteristic of broadband parametric amplification of incoherent light pulses in a 355-nm pumped degenerate picosecond optical parametric amplification with either saturated or unsaturated amplification. The optical parametric amplifier is seeded by the fluorescence generated in a solution of pyridine-1 dye in ethanol. With the saturated amplification, we can obtain high energy incoherent light pulses, whose full width at half maximum bandwidth varies from 16 nm to 53 nm for the different phase matching angles near degeneracy. Moreover, the unsaturated bandwidth of the amplified pulses fits well to the calculated result at degeneracy. Selecting s-polarized fluorescence with a Glan-Taylor prism, the maximum bandwidth of the amplified fluorescence is found to be 59 nm for a purely s-polarized seed. The maximum output energy is 0.67 mJ for the optical parametric amplifier. By using an optical filter and compressor, the generated high energy incoherent light has great potential as the incoherent pump, signal or idler wave of a parametric down-conversion process, so that a wave with a high degree of coherence can be generated from an incoherent pump light.
文摘In this paper, the solution of the time-dependent Fokker-Planck equation of non-degenerate optical parametric amplification is used to deduce the condition demonstrating the Einstein-Podolsky-Rosen （EPR） paradox. The analytics and numerical calculation show the influence of pump depletion on the error in the measurement of continuous variables. The optimum realization of EPR paradox can be achieved by adjusting the parameter of squeezing. This result is of practical importance when the realistic experimental conditions are taken into consideration .
基金Project supported by the National Basic Research Program of China (Grant Nos.2006CB806001 and 2011CB808101)the National Natural Science Foundation of China (Grant Nos.10734080,60908008,and 60921004)+1 种基金the Fund of the State Key Laboratory of High Field Laser Physics and Shanghai Commission of Science and Technology,China (Grant Nos.07JC14055 and 09QA1406500)and the Scientific Research Foundation of Zhejiang University of Technology,China (Grant No.109004129)
文摘A compact two-stage optical parametric chirped pulse amplifier based on photonic crystal fibre is demonstrated. A 1064-nm soliton pulse is obtained in a home-made photonic crystal fibre （PCF） with femtosecond pulse pumping and then amplified to 2 mJ in an Nd：YAG regenerative amplifier. After the amplified pulses pass through the LBO crystal, the 532-nm double-frequency light with an energy of 0.8 mJ and a duration of over 100 ps at 10-Hz repetition rate is generated as a pump source in the following two-stage optical parametric amplification （OPA）. The 850-nm chirped signal light gain from the stretcher is 1.5 × 10^4 in the first-stage OPA while it is 120 in the second-stage OPA. The total signal gain of optical parametric chirped pulse amplification （OPCPA） can reach 1.8 × 10^6.
基金Project supported by the Natural Science Foundation of Shanxi Province,China (Grant No. 2006011003)
文摘This paper applies the minimum variance V1 criterion to monitor the evolution of signal and idler modes of a composite non-degenerate optical parametric amplification （NOPA） system. The analytics and numerical calculation show the influence of the transition time, the vacuum fluctuations, and the thermal noise level on the EPR entanglement of the composite NOPA system. It finds that the entanglement and the squeezing degrade as the minimum variance V1 increases.
基金supported by Science and Technology Innovation Seedling Project of Sichuan Province,China(Grant No.2018100)Major Project of CDNU(Grant No.CS18ZDZ0511).
文摘Combined with the optical beam deflection,a novel approach of phase matched broadband scanning optical parametric chirped pulse amplification(OPCPA)was proposed.For this scheme,there was no superfluous operations to the chirped signal pulse which propagated in a changeless direction straightforward,but the pump beam were deflected in space with time by passing through a KTN crystal,which was applied with varied driving voltage.The theories of phase matching of each chirped signal frequency based on pump beam deflection was analyzed detailedly.And the type-I amplification of chirped signal with 800 nm central wavelength and 20 nm bandwidth pumped by 532 nm in BBO crystal was simulated as a case in point.The simulation results showed that the spectral distribution of chirped signal pulse was almost the same as the initial form,i.e.,there was nearly no narrowing on the amplified spectrum by using of the scanning OPCPA based on pump beam deflection.In addition,the simulations demonstrated that it was worth minimizing the voltage deviation applied to KTN crystal as much as possible for the sake of better waveform,larger bandwidth and higher conversion efficiency of amplified signal pulse in the proposed scanning OPCPA.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61378030 and 11127901)the National Basic Research Program of China(Grant No.2011CB808101)the International S&T Cooperation Program of China(Grant No.2011DFA11300)
文摘Since the proof-of-principle demonstration of optical parametric amplification to efficiently amplify chirped laser pulses in 1992, optical parametric chirped pulse amplification（OPCPA） became the most promising method for the amplification of broadband optical pulses. In the meantime, we are witnessing an exciting progress in the development of powerful and ultrashort pulse laser systems that employ chirped pulse parametric amplifiers. The output power and pulse duration of these systems have ranged from a few gigawatts to hundreds of terawatts with a potential of tens of petawatts power level. Meanwhile, the output pulse duration based on optical parametric amplification has entered the range of fewoptical-cycle field. In this paper, we overview the basic principles, trends in development, and current state of the ultrashort and laser systems based on OPCPA, respectively.
基金Project partially supported by the Shanghai Committee of Science and Technology, China (Grant Nos 05 SG 02 and 05 JC 14005)the National Natural Science Foundation of China (Grant Nos 60538010 and 10376009)
文摘This paper theoretically studies the double-pumped fibre-optical parametric amplifiers （FOPAs） in photonic crystal fibres. Two distinct working regimes of FOPAs are researched, which depend on the dispersion at the central wavelength of the two pumps. Extremely broad tuning range can be obtained when the central pump wavelength is in the normal dispersion regime and is insensitive to the wavelength separation between the two pumps, while the tuning range is narrow in the anomalous dispersion regime and can be significantly enhanced by increasing the wavelength separation. Impacts of higher-order dispersions and temporal walk-off on the gain spectra are also discussed.
基金We are grateful to Dr.D.Kaškelytėfor building a comprehensive literature database on OPCPA.We also would like to add the following dedication at the very end of the paper:This article is dedicated to the memory of Professor Algis Petras Piskarskas(1942-2022).
文摘The generation of power-and wavelength-scalable few optical cycle pulses remains one of the major challenges in modern laser physics.Over the past decade,the development of table-top optical parametric chirped pulse amplificationbased systems was progressing at amazing speed,demonstrating excellent performance characteristics in terms of pulse duration,energy,peak power and repetition rate,which place them at the front line of modern ultrafast laser technology.At present,table-top optical parametric chirped pulse amplifiers comprise a unique class of ultrafast light sources,which currently amplify octave-spanning spectra and produce carrier-envelope phase-stable,few optical cycle pulses with multi-gigawatt to multi-terawatt peak powers and multi-watt average powers,with carrier wavelengths spanning a considerable range of the optical spectrum.This article gives an overview on the state of the art of table-top optical parametric chirped pulse amplifiers,addressing their relevant scientific and technological aspects,and provides a short outlook of practical applications in the growing field of ultrafast science.
基金Project partially supported by the National Key R&D Program of of China(Grant No.2016YFA0301801)the National Natural Science Foundation of China(Grant Nos.61521001 and 61571219)PAPD,Dengfeng Project B of Nanjing University.
文摘An impedance matched parametric amplifier(IMPA)with Josephson junctions is fabricated and characterized.A hybrid structure containing coplanar and strip structures is implemented to realize an impedance taper line and a plate capacitor in an LC nonlinear resonator based on Josephson junctions.The upper plate of the capacitor is isolated with SiNx without grounding as well as the strips.Such easily-prepared designs greatly reduce the requirements for lithography alignment and precision,which makes the fabrication process more reliable.The experimental results show that in such IMPA a gain higher than 25 dB with a bandwidth of about 100 MHz can be obtained.This broadband amplifier operates close to the quantum limit.By adjusting the working point,a higher bandwidth of about 400 MHz can be obtained with a gain of about 17 dB.
基金Project supported by the National Basic Research Program of China (Grant No. 2010CB327605)the Discipline Co-construction Project of Beijing Municipal Commission of Education, China (Grant No. YB20081001301)the Fundamental Research Funds for Central Universities, China (Grant No. 2011RC008)
文摘In this paper, an analytical model to investigate the parametric amplification （PA） and the PA ＋ stimulated Raman scattering （SRS） in silicon waveguides is put forward. When two pump signals are employed, the PA bandwidth of the probe signal is so large that the Raman contribution has to be considered. When Raman contribution fraction f is set to be 0, only the PA occurs to amplify the probe signal, and when f is set to be 0.043, the PA and the SRS amplify the probe signal at the same time. The signal amplifications of both single and dual pump schemes are investigated by using this model. With this model, three main affecting factors, i.e., zero dispersion wavelength （ZDWL）, third-order dispersion （TOD）, and fourth-order dispersion （FOD）, are discussed in detail.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB921501)the National Natural Science Foundation of China(Grant Nos.11322439,11274165,11321063,and 91321312)+1 种基金the Dengfeng Project B of Nanjing University,Chinathe PAPD of Jiangsu Higher Education Institutions,China
文摘Surface plasmon polariton（SPP）, a sub-wavelength surface wave promising for photonic integration, always suffers from the large metallic loss that seriously restricts its practical application. Here, we propose a compact SPP amplifier based on a nonlinear hybrid waveguide（a combination of silver, LiNbO3, and SiO2）, where a couple of Bragg gratings are introduced in the waveguide to construct a cavity. This special waveguide is demonstrated to support a highly localized SPP-like hybrid mode and a low loss waveguide-like hybrid mode. To provide a large nonlinear gain, a pumping wave input from the LiNbO3 waveguide is designed to resonate inside the cavity and satisfy the cavity phase matching to fulfill the optical parametric amplification（OPA） of the SPP signal. Proper periods of gratings and the cavity length are chosen to satisfy the impedance matching condition to ensure the high input efficiency of the pump wave from the outside into the cavity. In theoretical calculations, this device demonstrates a high performance in a very compact scheme（~3.32 μm） and a much lower pumping power for OPA compared with single-pass pumping. To obtain a comprehensive insight into this cavity OPA, the influences of the pumping power, cavity length, and the initial phase are discussed in detail.
基金supported by the State Key Development Program for Basic Research of China (Grant No. 2010CB327605)the Discipline Co-construction Project of Beijing Municipal Commission of Education, China (Grant No. YB20081001301)the Fundamental Research Funds for Central Universities, China (Grant Nos. 2011RC008 and 2009RC0314)
文摘The performances of a dual-pump parametric and Raman amplification process and the wavelength conversion in silicon waveguides are investigated. By setting the Raman contribution fraction f to be 0.043 in our analytical model, the amplification gain of the probe signal can be obtained to be over 10 dB. The pump transfer noise （PTN）, the quantum noise （QN）, and the total noise figure （TNF） are discussed, and the TNF has a constant value of about 4 dB in the gain bandwidth. An idler signal generated during the parametric amplification （PA） process can be used to realize the wavelength conversion in wavelength division multiplexing （WDM） systems. In addition, the pump signal parameters, the generated free carrier lifetime and effective mode area （EMA） of the waveguide are analysed for the optimization of signal gain and noise characteristics.
基金Project supported by the National Basic Research Program,China (Grant No. 2006CB806007)the National Natural Science Foundation of China (Grant Nos. 10574006,10634020 and 10821062)
文摘We present an experimental investigation of a filamentation-assisted fourth-order nonlinear optical process in KTP crystals pumped by intense 1.53 eV （807 nm） femtosecond laser pulses. Femtosecond light pulses at 2.58 eV （480 nm） are generated by the fourth-order nonlinear polarization （p（4） （ω2） = X（4） （ω2, ω, ω, ω, -ω1）E3 （ω）E＊ （ω1）, where E（w） corresponds to the pump frequency and E（wl） to the supercontinuum generated through filamentation）. If the system is seeded by a laser beam at ω1 or ω2 and there are spatial and temporal overlaps with the pump beam, E（ω1） and E（ω2） are simultaneously amplified. When the intensity of the seed laser beam exceeds a certain intensity threshold, the contribution of p（4） （ω） = X（4） （ω, ω1, ω2, -ω, -ω）E（ω1）E（ω2）（E＊ （ω））2 becomes non-negligible, and the amplification weakens. The conversion efficiency from the pump to the signal at 2.58 eV （480 nm） attains to 0.1%.
