A. Gaydardzhiev, D. Draganov, I. Buchvarov, A. Stalnionis, A. Trifonov, T. Fiebig
Mode locking with frequency dependent nonlinear mirror of Nd:YAG laser with electro-optical negative feedback has been presented. We use a LBO based nonlinear mirror thermally stabilized at a temperature corresponding to noncritical phase matching of the frequency doubling at 1.064 μm. Employing a resonator polarization output detected by a fast photodiode we control resonator losses through a Pockels cell. By creating a negative feedback we achieved q-switch suppression, thus stabilizing the mode-locking regime. Through a simple theoretical model we derived a relation for the laser parameters for stable laser operation. We achieved a stable train of picosecond pulses grouped in the 200 microsecond pump macropulse. Macropulse output energy is 4 mJ at a pump repetition rate of 400 Hz. The picosecond pulse train frequency determined by the resonator length is 115 MHz.
{"title":"Generation of a train of ps-pulses from a diode pumped Nd-laser using electro-optical negative feedback","authors":"A. Gaydardzhiev, D. Draganov, I. Buchvarov, A. Stalnionis, A. Trifonov, T. Fiebig","doi":"10.1117/12.849944","DOIUrl":"https://doi.org/10.1117/12.849944","url":null,"abstract":"Mode locking with frequency dependent nonlinear mirror of Nd:YAG laser with electro-optical negative feedback has been presented. We use a LBO based nonlinear mirror thermally stabilized at a temperature corresponding to noncritical phase matching of the frequency doubling at 1.064 μm. Employing a resonator polarization output detected by a fast photodiode we control resonator losses through a Pockels cell. By creating a negative feedback we achieved q-switch suppression, thus stabilizing the mode-locking regime. Through a simple theoretical model we derived a relation for the laser parameters for stable laser operation. We achieved a stable train of picosecond pulses grouped in the 200 microsecond pump macropulse. Macropulse output energy is 4 mJ at a pump repetition rate of 400 Hz. The picosecond pulse train frequency determined by the resonator length is 115 MHz.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"176 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114940118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A fully quantum mechanical treatment is presented for the Cherenkov radiation stimulated by a uniformly moving charge particle in both isotopic medium and anisotropic medium. The relation between Cherenkov radiation intensity and dielectric tensor is analyzed, and the result is compared with previous work.
{"title":"Quantum theory of Cherenkov radiation in an anisotropic absorbing media","authors":"Wei Li, Chengxin Yu, Shibing Liu","doi":"10.1117/12.847455","DOIUrl":"https://doi.org/10.1117/12.847455","url":null,"abstract":"A fully quantum mechanical treatment is presented for the Cherenkov radiation stimulated by a uniformly moving charge particle in both isotopic medium and anisotropic medium. The relation between Cherenkov radiation intensity and dielectric tensor is analyzed, and the result is compared with previous work.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116659719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Gaydardzhiev, A. Trifonov, T. Fiebig, I. Buchvarov
A nanosecond Nd:YAG based high-energy kilohertz Master Oscillator Power Amplifier (MOPA) system has been developed. The Q-switched master oscillator emits 6.5-ns, 1-kHz pulses with energy up to 1.6 mJ. The design of the oscillator ensures TEM00 operation with high stability and insensitivity to cavity misalignment. Two different amplification schemes - slab and rod geometry of the amplifiers have been studied. We have developed a compact, five-pass gain module with slab design, pumped by four 30-W collimated laser diode bars. The amplified output energy is 8 mJ at 1 kHz. The optical-to-optical conversion efficiency is 15 %. The second scheme is based on side-pumped rod preamplifier with consequent end amplifier with depolarization compensation. This system delivers up to 18 mJ linearly polarized TEM00 pulses - corresponding to 5 % optical-to-optical conversion efficiency.
{"title":"High-power diode pumped Nd:YAG master oscillator power amplifier system","authors":"A. Gaydardzhiev, A. Trifonov, T. Fiebig, I. Buchvarov","doi":"10.1117/12.849859","DOIUrl":"https://doi.org/10.1117/12.849859","url":null,"abstract":"A nanosecond Nd:YAG based high-energy kilohertz Master Oscillator Power Amplifier (MOPA) system has been developed. The Q-switched master oscillator emits 6.5-ns, 1-kHz pulses with energy up to 1.6 mJ. The design of the oscillator ensures TEM00 operation with high stability and insensitivity to cavity misalignment. Two different amplification schemes - slab and rod geometry of the amplifiers have been studied. We have developed a compact, five-pass gain module with slab design, pumped by four 30-W collimated laser diode bars. The amplified output energy is 8 mJ at 1 kHz. The optical-to-optical conversion efficiency is 15 %. The second scheme is based on side-pumped rod preamplifier with consequent end amplifier with depolarization compensation. This system delivers up to 18 mJ linearly polarized TEM00 pulses - corresponding to 5 % optical-to-optical conversion efficiency.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116061419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Yoneda, Y. Inubushi, F. Sato, S. Morimoto, T. Kumagaya, M. Nagasono, A. Higashiya, M. Yabashi, T. Ishikawa, H. Ohashi, H. Kimura, T. Togashi, R. Kodama
In this work we report observation of ultra-fast switching of vacuum ultra-violet (VUV) light caused by saturable absorption by a solid metal foil. A sub-picosecond VUV pulse from a free-electron laser located in SPring-8 is focused on a metal target and transmission is measured as a function of input energy, thickness of the absorbing layer, and VUV laser wavelength. As is well known, metals have a strong linear free electron response associated with the plasma oscillation and collisional absorption (high-frequency resistivity). Due to the plasma screening and strong absorption, it is difficult to use bulk metals for optical components. However, above the plasma frequency as in our experiments, a metal can transmit light and shows phenomena related to the band gap structure, similar to the optical properties observed in transparent materials for visible and infrared light. We observe a strong gating of Sn transmission at energy fluences above 6J/cm2 at wavelength of 51nm. The ratio of the transmission at high intensity to low intensity is typically greater than 100:1. The estimated saturated transmittance is about 0.25. The mechanism of the switching phenomena is partially explained by the shift of Sn N shell band edge, however, more details should be investigated with more exact physical models and precise measurements. We think this is the first observation of such a strong nonlinear phenomena for VUV light and this result will promote the development of new nonlinear photonic devices such as auto-correlator and pulse slicer for the VUV region.
{"title":"Observation of saturable absorption of Sn metal film with intense EUV laser pulse","authors":"H. Yoneda, Y. Inubushi, F. Sato, S. Morimoto, T. Kumagaya, M. Nagasono, A. Higashiya, M. Yabashi, T. Ishikawa, H. Ohashi, H. Kimura, T. Togashi, R. Kodama","doi":"10.1117/12.850908","DOIUrl":"https://doi.org/10.1117/12.850908","url":null,"abstract":"In this work we report observation of ultra-fast switching of vacuum ultra-violet (VUV) light caused by saturable absorption by a solid metal foil. A sub-picosecond VUV pulse from a free-electron laser located in SPring-8 is focused on a metal target and transmission is measured as a function of input energy, thickness of the absorbing layer, and VUV laser wavelength. As is well known, metals have a strong linear free electron response associated with the plasma oscillation and collisional absorption (high-frequency resistivity). Due to the plasma screening and strong absorption, it is difficult to use bulk metals for optical components. However, above the plasma frequency as in our experiments, a metal can transmit light and shows phenomena related to the band gap structure, similar to the optical properties observed in transparent materials for visible and infrared light. We observe a strong gating of Sn transmission at energy fluences above 6J/cm2 at wavelength of 51nm. The ratio of the transmission at high intensity to low intensity is typically greater than 100:1. The estimated saturated transmittance is about 0.25. The mechanism of the switching phenomena is partially explained by the shift of Sn N shell band edge, however, more details should be investigated with more exact physical models and precise measurements. We think this is the first observation of such a strong nonlinear phenomena for VUV light and this result will promote the development of new nonlinear photonic devices such as auto-correlator and pulse slicer for the VUV region.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130806505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We analyze a class of multicomponent nonlinear Schrödinger equations (MNLS) related to the symmetric BD.I-type symmetric spaces and their reductions. We briefly outline the direct and the inverse scattering method for the relevant Lax operators and the soliton solutions. We use the Zakharov-Shabat dressing method to obtain the two-soliton solution and analyze the soliton interactions of the MNLS equations and some of their reductions.
{"title":"Bose-Einstein condensates with F=1 and F=2: reductions and soliton interactions of multi-component NLS models","authors":"V. Gerdjikov, N. Kostov, T. Valchev","doi":"10.1117/12.849184","DOIUrl":"https://doi.org/10.1117/12.849184","url":null,"abstract":"We analyze a class of multicomponent nonlinear Schrödinger equations (MNLS) related to the symmetric BD.I-type symmetric spaces and their reductions. We briefly outline the direct and the inverse scattering method for the relevant Lax operators and the soliton solutions. We use the Zakharov-Shabat dressing method to obtain the two-soliton solution and analyze the soliton interactions of the MNLS equations and some of their reductions.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"7501 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131059243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Description of optical system with saturable amplification, saturable losses and filtering9-10 (see also11-12) is studied. The aim of this work is to derive the system of ode's, that extends the earlier one1-2, including additionally the temporal dependences of the saturated gain and losses. First, this extended system is applied to the case of fast changes in the amplification and losses7-8. Regarding the dissipative solitons, earlier results7-8 have been confirmed. In addition, nonlinear fixed points have been also studied and as result fronts were identified. Next, the extended system is applied to the case of temporal dependent amplification and losses9-10. Linear and nonlinear fixed points of this system have been calculated and their stability identified. Typical solutions discussed earlier9 have been found. Fronts have been also revealed. Phase space interpretation of obtained coherent structures is given.
{"title":"Dissipative finite degrees of freedom dynamical system and description of optical systems with saturable amplification, saturable losses, and filtering","authors":"I. Uzunov","doi":"10.1117/12.853425","DOIUrl":"https://doi.org/10.1117/12.853425","url":null,"abstract":"Description of optical system with saturable amplification, saturable losses and filtering9-10 (see also11-12) is studied. The aim of this work is to derive the system of ode's, that extends the earlier one1-2, including additionally the temporal dependences of the saturated gain and losses. First, this extended system is applied to the case of fast changes in the amplification and losses7-8. Regarding the dissipative solitons, earlier results7-8 have been confirmed. In addition, nonlinear fixed points have been also studied and as result fronts were identified. Next, the extended system is applied to the case of temporal dependent amplification and losses9-10. Linear and nonlinear fixed points of this system have been calculated and their stability identified. Typical solutions discussed earlier9 have been found. Fronts have been also revealed. Phase space interpretation of obtained coherent structures is given.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130876149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Pálfalvi, K. Lengyel, Á. Péter, J. Fülöp, T. Reiter, J. Hebling
Z-scan is a well established sensitive and accurate technique used to determine nonlinear absorption and refraction. In this paper a review-like study of the Z-scan applications for the examination of LiNbO3 crystals with different stoichiometry and with different dopants will be presented. By the extension standard Z-scan setup the cubic, the thermo-optical and the photorefractive nonlinearity can be examined. Theoretical calculations together with the measurements make possible to characterize quantitatively the thermo-optical nonlinearity and to determine the threshold dopant concentration of the photorefractive damage which is very important for nonlinear optical applications. Pure and Mg doped stoichiometric as well as congruent, and In, Hf, Zr or Y/Mg doped congruent LN samples were examined. Furthermore, a Z-scan theory based on the solution of the nonlinear paraxial wave equation, completed by the Huygens-Fresnel principle is introduced. This theory is valid for the general case, i.e. for thick samples and strong nonlinearities including both nonlinear refraction and absorption.
{"title":"Theoretical and experimental development of the Z-scan method and its application for the characterization of LiNbO3","authors":"L. Pálfalvi, K. Lengyel, Á. Péter, J. Fülöp, T. Reiter, J. Hebling","doi":"10.1117/12.849871","DOIUrl":"https://doi.org/10.1117/12.849871","url":null,"abstract":"Z-scan is a well established sensitive and accurate technique used to determine nonlinear absorption and refraction. In this paper a review-like study of the Z-scan applications for the examination of LiNbO3 crystals with different stoichiometry and with different dopants will be presented. By the extension standard Z-scan setup the cubic, the thermo-optical and the photorefractive nonlinearity can be examined. Theoretical calculations together with the measurements make possible to characterize quantitatively the thermo-optical nonlinearity and to determine the threshold dopant concentration of the photorefractive damage which is very important for nonlinear optical applications. Pure and Mg doped stoichiometric as well as congruent, and In, Hf, Zr or Y/Mg doped congruent LN samples were examined. Furthermore, a Z-scan theory based on the solution of the nonlinear paraxial wave equation, completed by the Huygens-Fresnel principle is introduced. This theory is valid for the general case, i.e. for thick samples and strong nonlinearities including both nonlinear refraction and absorption.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130406665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A 2D study in focus point of two identical femtosecond laser sources introducing a temporal displacement for ultra-short pulses generation based on Coherent Beam Combining was developed. This study is based on numerical simulation which shows the spatial and temporal properties of the electromagnetic field. The piston error is introduced by moving one of these two laser sources in the same direction, while the other laser source is fixed. The interval considered for the laser source displacement (piston error) is between lambda/10 and 40 lambda. The results are relevant for the coherent beam combination at the Extreme Light Infrastructure facility.
{"title":"Spatial and temporal dynamics of ultra-short pulses coherent beam combining","authors":"D. Ursescu, L. Ionel","doi":"10.1117/12.849441","DOIUrl":"https://doi.org/10.1117/12.849441","url":null,"abstract":"A 2D study in focus point of two identical femtosecond laser sources introducing a temporal displacement for ultra-short pulses generation based on Coherent Beam Combining was developed. This study is based on numerical simulation which shows the spatial and temporal properties of the electromagnetic field. The piston error is introduced by moving one of these two laser sources in the same direction, while the other laser source is fixed. The interval considered for the laser source displacement (piston error) is between lambda/10 and 40 lambda. The results are relevant for the coherent beam combination at the Extreme Light Infrastructure facility.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130422904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using the spectral approach for description of the processes in nonlinear optics, by numerical calculations we obtain the dependences of the third harmonic generation (THG) on the output spectra and spectral energy, spectral width and spectral barycenter in the presence of quadratic and cubic spectral phase terms in the input. The main equation that describes the evolution of the spectral properties for the process of THG is derived. The suggested model could be applied also for analysis of a few order high harmonics.
{"title":"Phase modulation in the process of third harmonic generation","authors":"I. Ivanov, S. Saltiel","doi":"10.1117/12.850864","DOIUrl":"https://doi.org/10.1117/12.850864","url":null,"abstract":"Using the spectral approach for description of the processes in nonlinear optics, by numerical calculations we obtain the dependences of the third harmonic generation (THG) on the output spectra and spectral energy, spectral width and spectral barycenter in the presence of quadratic and cubic spectral phase terms in the input. The main equation that describes the evolution of the spectral properties for the process of THG is derived. The suggested model could be applied also for analysis of a few order high harmonics.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"279 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122853007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We describe the fabrication and characterization of partially ordered 2D photonic structures prepared by domain inversion in LiNbO3. Two types of structures have been prepared: (i) decagonal quasi-crystals designed by tiling the plane with different kinds of rhomb shaped tiles and (ii) a short-range ordered structure designed by placing randomly oriented basic units on a square lattice. Both types of structures exhibit rich sets of reciprocal vectors that may be used to satisfy the phase matching conditions for different nonlinear optical processes. As examples we describe collinear second harmonic generation of multiple wavelengths in a single decagonal nonlinear photonic quasi-crystal and cascaded third harmonic generation in a short range order nonlinear photonic crystal.
{"title":"Two-dimensional nonlinear photonic quasi-crystals: design, characterization, and applications","authors":"Y. Sheng, K. Koynov, S. Saltiel","doi":"10.1117/12.848740","DOIUrl":"https://doi.org/10.1117/12.848740","url":null,"abstract":"We describe the fabrication and characterization of partially ordered 2D photonic structures prepared by domain inversion in LiNbO3. Two types of structures have been prepared: (i) decagonal quasi-crystals designed by tiling the plane with different kinds of rhomb shaped tiles and (ii) a short-range ordered structure designed by placing randomly oriented basic units on a square lattice. Both types of structures exhibit rich sets of reciprocal vectors that may be used to satisfy the phase matching conditions for different nonlinear optical processes. As examples we describe collinear second harmonic generation of multiple wavelengths in a single decagonal nonlinear photonic quasi-crystal and cascaded third harmonic generation in a short range order nonlinear photonic crystal.","PeriodicalId":155856,"journal":{"name":"Ultrafast Nonlinear Optics","volume":"7501 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129798781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：