The results of the own experimental and theoretical investigations of the long-lived photon echo (LPE) are reported. The special type of the resonant media, named as Van-Vleck paramagnetics (for example, LaF3:Pr3+), is used in our experiments. The physical mechanisms of LPE-forming are studied in these experiments. The various problems of the optical storage, using LPE, are discussed.
{"title":"Long-Lived Photon Echo in Van-Vleck Paramagnetics: Physics and Optical Storage","authors":"V. V. Samartsev","doi":"10.1364/shbs.1994.wd61","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd61","url":null,"abstract":"The results of the own experimental and theoretical investigations of the long-lived photon echo (LPE) are reported. The special type of the resonant media, named as Van-Vleck paramagnetics (for example, LaF3:Pr3+), is used in our experiments. The physical mechanisms of LPE-forming are studied in these experiments. The various problems of the optical storage, using LPE, are discussed.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129936129","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}
Photo induced spectral changes of some molecules containing electronic π systems are investigated and the effect of electrocyclic reactions (ring closure etc) on their electronic structure is considered. Two types of molecules are studied 1) Molecules which exhibit two stable states characterized by different π electron configurations1) such as 2) electron transfer systems containing a "π electron bridge" linking donor and acceptor which can be modified by a photo induced reaction for example Static electronic π systems are described by a nearest neighbor Huckel Theory, i.e. by a Hamiltonian of the type where ai+, ai are the usual Fermion creation and destruction operators, ε the p electron energy and Γij the coupling between nearest neighbor p orbitals. Due to rotation of molecular fragments Γij depends on the orientation of the relevant p orbitals.
{"title":"Theoretical Models for Photochromic Systems","authors":"E. Canel","doi":"10.1364/shbs.1994.wd45","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd45","url":null,"abstract":"Photo induced spectral changes of some molecules containing electronic π systems are investigated and the effect of electrocyclic reactions (ring closure etc) on their electronic structure is considered. Two types of molecules are studied\u0000 1) Molecules which exhibit two stable states characterized by different π electron configurations1) such as\u0000 2) electron transfer systems containing a \"π electron bridge\" linking donor and acceptor which can be modified by a photo induced reaction for example\u0000 Static electronic π systems are described by a nearest neighbor Huckel Theory, i.e. by a Hamiltonian of the type\u0000 where ai+, ai are the usual Fermion creation and destruction operators, ε the p electron energy and Γij the coupling between nearest neighbor p orbitals. Due to rotation of molecular fragments Γij depends on the orientation of the relevant p orbitals.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116460999","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}
W. Moerner, S. Silence, G. Bjorklund, D. Burland, R. D. Miller, J. Stankus, R. Twieg
In the past few years, a new class of polymeric materials for photonic applications has appeared called photorefractive (PR) polymers. Photorefractivity is defined as modulation of the index of refraction in an electro-optic material by internal electric fields produced by optical redistribution of charge carriers; hence it must not be confused with local mechanisms of index change such as photochromism, excited state population, heating, etc. When a material shows the required properties of charge generation, transport, trapping, and dependence of the index of refraction upon the internal electric field, it can be tested for photorefractivity by observation of asymmetric energy transfer (two-beam coupling) between two laser beams in the material.
{"title":"Science and Applications of Photorefractive Polymeric Materials","authors":"W. Moerner, S. Silence, G. Bjorklund, D. Burland, R. D. Miller, J. Stankus, R. Twieg","doi":"10.1364/shbs.1994.fa1","DOIUrl":"https://doi.org/10.1364/shbs.1994.fa1","url":null,"abstract":"In the past few years, a new class of polymeric materials for photonic applications has appeared called photorefractive (PR) polymers. Photorefractivity is defined as modulation of the index of refraction in an electro-optic material by internal electric fields produced by optical redistribution of charge carriers; hence it must not be confused with local mechanisms of index change such as photochromism, excited state population, heating, etc. When a material shows the required properties of charge generation, transport, trapping, and dependence of the index of refraction upon the internal electric field, it can be tested for photorefractivity by observation of asymmetric energy transfer (two-beam coupling) between two laser beams in the material.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127442250","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}
Stochastic models to describe the inhomogeneous broadening of electronic transitions of dye molecules in amorphous hosts [1] and to account for the effects of external hydrostatic pressure on spectral holes [2] have been applied to analyze experimental results obtained in a variety of samples, with hosts ranging from polymers to aerogels. With these models it was possible to determine the compressibilities of various polymers by purely optical experiments. It is interesting that these results are in agreement with mechanically obtained data within approx. 15%. Furthermore, the depth ϵ of the assumed Lennard-Jones dye-matrix interaction potential could be calculated.
{"title":"Analysis of the Importance of Matrix Correlations through Hole-Burning Experiments in Dye-Doped Rare Gas Matrices","authors":"P. Geissinger, L. Kador, T. Giering, D. Haarer","doi":"10.1364/shbs.1994.wd48","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd48","url":null,"abstract":"Stochastic models to describe the inhomogeneous broadening of electronic transitions of dye molecules in amorphous hosts [1] and to account for the effects of external hydrostatic pressure on spectral holes [2] have been applied to analyze experimental results obtained in a variety of samples, with hosts ranging from polymers to aerogels. With these models it was possible to determine the compressibilities of various polymers by purely optical experiments. It is interesting that these results are in agreement with mechanically obtained data within approx. 15%. Furthermore, the depth ϵ of the assumed Lennard-Jones dye-matrix interaction potential could be calculated.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133781873","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}
Recent low-temperature spectroscopic studies of chromophores encapsulated in the Å-scale porous cage and channel structures of inorganic molecular sieves have revealed a number of properties absent for chromophors in solid bulk solutions. For example, thionine in a dehydrated zeolite-Y exhibits two distinguishable ground state forms which are associated with a reorientation of the chromophor with respect to the surrounding zeolite cage [1]. This additional degree of freedom which depends on specific relationship between the size of the molecular guest and void of the host gives rise to a new kind of low-temperature photochemistry. In general, however, spectral hole-burning is only feasible if the pores of the molecular sieve are filled with solvent as additional coadsorbate. In samples of this kind the coadsorbate acts as an amorphous solvent shell containing two-level systems (TLSs) which gives rise to non-photochemical hole-burning similar to bulk amorphous systems. In fact, a phthalocyanine-zinc derivative embedded in a hydrated AIPO4-5 molecular sieve allow efficient hole formation up to 80 K, the highest temperature for which stable non-photochemical holes have been reported so far [2].
{"title":"Low-Temperature Spectroscopy of Chromophores in Geometrically Restricted Amorphous Phases","authors":"F. Deeg, H. W. Kindervater, C. Bräuchle","doi":"10.1364/shbs.1994.wd46","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd46","url":null,"abstract":"Recent low-temperature spectroscopic studies of chromophores encapsulated in the Å-scale porous cage and channel structures of inorganic molecular sieves have revealed a number of properties absent for chromophors in solid bulk solutions. For example, thionine in a dehydrated zeolite-Y exhibits two distinguishable ground state forms which are associated with a reorientation of the chromophor with respect to the surrounding zeolite cage [1]. This additional degree of freedom which depends on specific relationship between the size of the molecular guest and void of the host gives rise to a new kind of low-temperature photochemistry. In general, however, spectral hole-burning is only feasible if the pores of the molecular sieve are filled with solvent as additional coadsorbate. In samples of this kind the coadsorbate acts as an amorphous solvent shell containing two-level systems (TLSs) which gives rise to non-photochemical hole-burning similar to bulk amorphous systems. In fact, a phthalocyanine-zinc derivative embedded in a hydrated AIPO4-5 molecular sieve allow efficient hole formation up to 80 K, the highest temperature for which stable non-photochemical holes have been reported so far [2].","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115781258","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}
The change in infrared reflection spectra of natural silicates caused by CO2 laser action on the surface of these matters has been investigated. The matters mentioned above have intensive inhomogeneously broadened infrared absorbtion band of assymmetric valent Si-O-Si vibrations at the range of laser action, that provide intensive absorbtion of laser energy. The laser action on these matters lead to the intensive sublimation of matter with torch formation at the irradiated surface.
{"title":"Photochemical indused change in infrared reflection spectra of silicates","authors":"A. F. Mukhamedgalieva, A. M. Bondaŕ","doi":"10.1364/shbs.1994.wd60","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd60","url":null,"abstract":"The change in infrared reflection spectra of natural silicates caused by CO2 laser action on the surface of these matters has been investigated. The matters mentioned above have intensive inhomogeneously broadened infrared absorbtion band of assymmetric valent Si-O-Si vibrations at the range of laser action, that provide intensive absorbtion of laser energy. The laser action on these matters lead to the intensive sublimation of matter with torch formation at the irradiated surface.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131894812","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}
Photochemical spectral hole-burning (PSHB) has attracted particular attention in the past decade because of its potential for frequency domain optical storage. In order to apply PSHB to a practical optical memory, the material should have high burning temperature, high thermal stability, erasability and high frequency multiplexing. Two ways are possible to increase the storage density: one is to narrow the homogeneous line width, the other is to broaden the inhomogeneous line width. In previous works, the larger inhomogeneous line width (greater than 1,000 cm–1) has been reached in polymethylmethacrylate (PMMA) doped with two kinds of Zn-benzoporphyrin derivatives with roughly the same hole-burning efficiencies [1]. In this paper, the authors investigate systematically the optical properties of Zn-benzoporphyrin derivatives, their hole-burning mechanisms, thermal stability and electron-phonon coupling in cellulose acetate (CA) and in PMMA matrices. The choice of CA was motivated mainly by the fact this polymer allows to prepare samples with excellent optical quality.
{"title":"Photon-Gated Spectral Hole-Burning in a Polymer Doped with a Mixture of Several Zn-Benzoporphyrin Derivatives","authors":"B. Luo, J. Galaup","doi":"10.1364/shbs.1994.wd28","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd28","url":null,"abstract":"Photochemical spectral hole-burning (PSHB) has attracted particular attention in the past decade because of its potential for frequency domain optical storage. In order to apply PSHB to a practical optical memory, the material should have high burning temperature, high thermal stability, erasability and high frequency multiplexing. Two ways are possible to increase the storage density: one is to narrow the homogeneous line width, the other is to broaden the inhomogeneous line width. In previous works, the larger inhomogeneous line width (greater than 1,000 cm–1) has been reached in polymethylmethacrylate (PMMA) doped with two kinds of Zn-benzoporphyrin derivatives with roughly the same hole-burning efficiencies [1]. In this paper, the authors investigate systematically the optical properties of Zn-benzoporphyrin derivatives, their hole-burning mechanisms, thermal stability and electron-phonon coupling in cellulose acetate (CA) and in PMMA matrices. The choice of CA was motivated mainly by the fact this polymer allows to prepare samples with excellent optical quality.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121801061","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}
K. Dou, Jisen Zhang, M. Tian, Jiahua Zhang, C. Jin, Jialong Zhao, Shi-hua Huang, Jiaqi Yu
In our previous works, some holeburning results in organic materials with charge transfer were given. We achieved the photon-gated holeburning in a system containing the electron acceptor (p-hydroxybenzaldhyde (PHBA)) and the electron donor (Zn-tetraphenylbenzoporphyrin (Zn-TPBP) doped in a matrix (poly-methylmethacrylate (PMMA) ) [1-3]. In this paper, we will report the single photon holeburning at 25K in p- tetraphenylporphyrin (TPP) embedded in the matrix of polymethylcellulose. The mechanisms of holeburning and holefilling are discussed.
{"title":"Spectral Holeburning in Tetraphenylporphyrin Doped Polymethylcellulose","authors":"K. Dou, Jisen Zhang, M. Tian, Jiahua Zhang, C. Jin, Jialong Zhao, Shi-hua Huang, Jiaqi Yu","doi":"10.1364/shbs.1994.wd40","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd40","url":null,"abstract":"In our previous works, some holeburning results in organic materials with charge transfer were given. We achieved the photon-gated holeburning in a system containing the electron acceptor (p-hydroxybenzaldhyde (PHBA)) and the electron donor (Zn-tetraphenylbenzoporphyrin (Zn-TPBP) doped in a matrix (poly-methylmethacrylate (PMMA) ) [1-3]. In this paper, we will report the single photon holeburning at 25K in p- tetraphenylporphyrin (TPP) embedded in the matrix of polymethylcellulose. The mechanisms of holeburning and holefilling are discussed.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127749304","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}
Fluorescence excitation spectroscopy of single dye molecules in crystals offers the possibility to determine molecular paramaters of single absorbers and their distribution instead of ensemble averages [1,2]. Informations about single molecules can be derived from the optical absorption spectra and from the time distribution of the fluorescence photons. The inhomogeneous broadening of an electronic transition reflects the variety of local environments accessible to the guest molecules and is therefore a measure for the degree of disorder or the defect concentration in the host crystal [3,4]. For pentacene molecules in p-terphenyl crystals (c ≈ 10−8mole/mole) we observed different types of inhomogeneous broadening: Some crystals show a narrow (FWHM ≈ 1 GHz) Lorentzian line with a satellite structure at short wavelengths due to 13C substitutional isomers of pentacene. The inhomogeneous line of other crystals is remarkable broadened and neither Lorentzian nor Gaussian. The intersystem crossing (ISC) rates k23 and k31 can be determined by measuring the intensity autocorrelation function of the fluorescence light [5]. In a crystal with low degree of disorder (narrow Lorentzian inhomogeneous broadening) the ISC rates of the molecules show a smaller distribution than in a crystal with higher degree of disorder (broadened line). The fully saturated fluorescence emission rates as calculated using the ISC rates are consistent with the experimentally measured photocount rates.
{"title":"Optical Spectroscopy of Single Pentacene Molecules in Disordered p-Terphenyl Crystals","authors":"S. Rummer, T. Basché, C. Bräuchle","doi":"10.1364/shbs.1994.wd3","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd3","url":null,"abstract":"Fluorescence excitation spectroscopy of single dye molecules in crystals offers the possibility to determine molecular paramaters of single absorbers and their distribution instead of ensemble averages [1,2]. Informations about single molecules can be derived from the optical absorption spectra and from the time distribution of the fluorescence photons. The inhomogeneous broadening of an electronic transition reflects the variety of local environments accessible to the guest molecules and is therefore a measure for the degree of disorder or the defect concentration in the host crystal [3,4]. For pentacene molecules in p-terphenyl crystals (c ≈ 10−8mole/mole) we observed different types of inhomogeneous broadening: Some crystals show a narrow (FWHM ≈ 1 GHz) Lorentzian line with a satellite structure at short wavelengths due to 13C substitutional isomers of pentacene. The inhomogeneous line of other crystals is remarkable broadened and neither Lorentzian nor Gaussian. The intersystem crossing (ISC) rates k23 and k31 can be determined by measuring the intensity autocorrelation function of the fluorescence light [5]. In a crystal with low degree of disorder (narrow Lorentzian inhomogeneous broadening) the ISC rates of the molecules show a smaller distribution than in a crystal with higher degree of disorder (broadened line). The fully saturated fluorescence emission rates as calculated using the ISC rates are consistent with the experimentally measured photocount rates.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114670964","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}
The optical switching devices in optical computing systems usually use electro-, acousto- optic and nonlinear optical effects. Photochemical reactions can be potentially used as one of the principles for photo-optical switching devices, because they change the electric structure of the system.1 In this study, the change in refractive indices of PMMA films containing DAAB (p- dimethylaminoazobenzene) during photoisomerization and the birefringence during polarized-light induced photoisomerization were measured, and the possibility as a photo-optical controlling material was examined.
{"title":"The Change in Refractive Index and the Formation of Birefringence during Photoisomerization of Photochromic Dyes","authors":"S. Morino, K. Horie, T. Yamashita","doi":"10.1364/shbs.1994.wd42","DOIUrl":"https://doi.org/10.1364/shbs.1994.wd42","url":null,"abstract":"The optical switching devices in optical computing systems usually use electro-, acousto- optic and nonlinear optical effects. Photochemical reactions can be potentially used as one of the principles for photo-optical switching devices, because they change the electric structure of the system.1 In this study, the change in refractive indices of PMMA films containing DAAB (p- dimethylaminoazobenzene) during photoisomerization and the birefringence during polarized-light induced photoisomerization were measured, and the possibility as a photo-optical controlling material was examined.","PeriodicalId":443330,"journal":{"name":"Spectral Hole-Burning and Related Spectroscopies: Science and Applications","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129790934","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}
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