Pub Date : 2003-06-27DOI: 10.1109/CLEOE.2003.1313819
J. Solís, S. M. Wiggins, C. Afonso
Nonstoichiometric, Sb-rich, amorphous thin films, such as Sb/sub x/Ge/sub 1-x/ with x>0.85 have been demonstrated to be promising candidates for the development of ultrashort laser pulse driven rewritable phase change optical disks. In this work we have investigated the joint influence of the film thickness, wavelength and pulse duration on the transformation time between the crystalline and the amorphous phases of GeSb films under picosecond and femtosecond laser pulses aiming to find routes for further improvements of the transformation time.
{"title":"Can the transformation time in phase change optical recording be improved by using femtosecond laser pulses?","authors":"J. Solís, S. M. Wiggins, C. Afonso","doi":"10.1109/CLEOE.2003.1313819","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313819","url":null,"abstract":"Nonstoichiometric, Sb-rich, amorphous thin films, such as Sb/sub x/Ge/sub 1-x/ with x>0.85 have been demonstrated to be promising candidates for the development of ultrashort laser pulse driven rewritable phase change optical disks. In this work we have investigated the joint influence of the film thickness, wavelength and pulse duration on the transformation time between the crystalline and the amorphous phases of GeSb films under picosecond and femtosecond laser pulses aiming to find routes for further improvements of the transformation time.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"1 1","pages":"742-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89669360","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1312362
C. García-Lara, E. Hernández-Hernández, S. Mansurova, R. Ramos-García
In this paper, we have shown that by using beating of two photo-emf signals generated by two incoherent patterns, each at oscillating at different frequencies and not at the same spatial frequency and phase modulation amplitude, can be used to determine the frequency components of a vibrating object.
{"title":"Frequency spectral analyzer using photo-EMF effect","authors":"C. García-Lara, E. Hernández-Hernández, S. Mansurova, R. Ramos-García","doi":"10.1109/CLEOE.2003.1312362","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1312362","url":null,"abstract":"In this paper, we have shown that by using beating of two photo-emf signals generated by two incoherent patterns, each at oscillating at different frequencies and not at the same spatial frequency and phase modulation amplitude, can be used to determine the frequency components of a vibrating object.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"2 1","pages":"301-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73436247","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1312340
S. Gille, R. Radouani, J. Salvestrini, F. Abdi, L. Guilbert, M. Fontana
Lithium niobate LiNbO/sub 3/ (LN) Mach-Zehnder interferometer (MZI) modulators are a key in high-speed optical communication systems. The optimization of integrated Mach-Zehnder interferometer modulator is discussed in this paper. We have extensively characterized the drift phenomena in a typical MZI modulator as a function of time, temperature and optical power. We have carried out optical and electrical measurements of the characteristics of the passive component and the active component as well. We also took into account of other physical properties such as pyroelectric effect, photovoltaic effect and photoconductivity. The electrical characteristics of the wafer and component were investigated and reported here. We present here the first results of the simulations which were obtained in this frame. These predictions are then compared with the effective electric field in the different layers and its time behavior.
{"title":"Optimization of integrated Mach-Zehnder interferometer modulator: electrical and optical studies","authors":"S. Gille, R. Radouani, J. Salvestrini, F. Abdi, L. Guilbert, M. Fontana","doi":"10.1109/CLEOE.2003.1312340","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1312340","url":null,"abstract":"Lithium niobate LiNbO/sub 3/ (LN) Mach-Zehnder interferometer (MZI) modulators are a key in high-speed optical communication systems. The optimization of integrated Mach-Zehnder interferometer modulator is discussed in this paper. We have extensively characterized the drift phenomena in a typical MZI modulator as a function of time, temperature and optical power. We have carried out optical and electrical measurements of the characteristics of the passive component and the active component as well. We also took into account of other physical properties such as pyroelectric effect, photovoltaic effect and photoconductivity. The electrical characteristics of the wafer and component were investigated and reported here. We present here the first results of the simulations which were obtained in this frame. These predictions are then compared with the effective electric field in the different layers and its time behavior.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"56 1","pages":"279-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73499357","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1313524
J. Trull, Stefano Minardi, P. Trapani, O. Jedrkiewicz, Marco A. C. Potenza, A. Matijošius, G. Valiulis, A. Varanavičius, R. Danielius, A. Piskarskas, E. Kučinskas
Three-dimensional reconstruction of light wave-packets with complex spatio-temporal profiles is obtained by means of a second order cross-correlation scheme with a transverse and temporal resolution of few tens of microns and of femtoseconds respectively.
{"title":"Three-dimensional reconstruction of nonlinear wavepackets using a temporal gate","authors":"J. Trull, Stefano Minardi, P. Trapani, O. Jedrkiewicz, Marco A. C. Potenza, A. Matijošius, G. Valiulis, A. Varanavičius, R. Danielius, A. Piskarskas, E. Kučinskas","doi":"10.1109/CLEOE.2003.1313524","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313524","url":null,"abstract":"Three-dimensional reconstruction of light wave-packets with complex spatio-temporal profiles is obtained by means of a second order cross-correlation scheme with a transverse and temporal resolution of few tens of microns and of femtoseconds respectively.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"39 1","pages":"461-462"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73660730","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1312329
Y. He, B. Orr
Our novel approach to wavelength-control of a pulsed tunable OPO combines the versatility and wavelength-agility of a grating or etalon with the modularity of injection seeding. We use a wavelength-selective tunable filter (WSTF) external to the OPO cavity, accessing a wider range of wavelengths than with convenient TDL seed sources. The new narrowband tunable OPO system is based on quasiphase-matched (QPM) nonlinear optical media. In summary, a narrowband, ns-pulsed QPM OPO tuned by a wavelength-selective feedback module external to the OPO ring cavity is demonstrated.
{"title":"Single-longitudinal-mode tuning of a pulsed optical parametric oscillator by wavelength-selective feedback","authors":"Y. He, B. Orr","doi":"10.1109/CLEOE.2003.1312329","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1312329","url":null,"abstract":"Our novel approach to wavelength-control of a pulsed tunable OPO combines the versatility and wavelength-agility of a grating or etalon with the modularity of injection seeding. We use a wavelength-selective tunable filter (WSTF) external to the OPO cavity, accessing a wider range of wavelengths than with convenient TDL seed sources. The new narrowband tunable OPO system is based on quasiphase-matched (QPM) nonlinear optical media. In summary, a narrowband, ns-pulsed QPM OPO tuned by a wavelength-selective feedback module external to the OPO ring cavity is demonstrated.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"66 1","pages":"268-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74076157","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1312366
J. Reményi, E. Lőrincz
In this paper, the temporal coherence function of a frequency-doubled multimode Nd:YAG laser (532 nm, 50 mW) has been investigated by measuring the diffraction efficiency of the polarization holographic gratings written by the laser in photoanisotropic polymer. The power spectrum of the laser-beam has also been measured by a grating spectrometer. From the measured spectrum the coherence function has been calculated. At the Fourier transformation measured spectrum has been approximated by a linear combination of three /spl delta/-function with different amplitudes.
{"title":"Coherence function measurement of a multimode laser by polarization holography","authors":"J. Reményi, E. Lőrincz","doi":"10.1109/CLEOE.2003.1312366","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1312366","url":null,"abstract":"In this paper, the temporal coherence function of a frequency-doubled multimode Nd:YAG laser (532 nm, 50 mW) has been investigated by measuring the diffraction efficiency of the polarization holographic gratings written by the laser in photoanisotropic polymer. The power spectrum of the laser-beam has also been measured by a grating spectrometer. From the measured spectrum the coherence function has been calculated. At the Fourier transformation measured spectrum has been approximated by a linear combination of three /spl delta/-function with different amplitudes.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"12 1","pages":"305-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74907682","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1313802
D. M. Pennington, R. Beach, J. Dawson, A. Drobshoff, Z. Liao, S. Payne, D. Bonaccini, W. Hackenberg, L. Taylor
We are developing an all-fiber laser system for generating 589 nm light for laser-guided adaptive optics. If only natural stars can be used to measure the turbulence in the Earth's atmosphere, at most a few percent of the sky is accessible to adaptive optics correction. Laser guide stars are therefore crucial to the broad use of adaptive optics, because they facilitate access to a large fraction of possible locations on the sky. In particular, lasers tuned to the 589 nm resonance line of atomic sodium are able to create an artificial beacon at altitudes of 95-105 km, thus coming as close as possible to reproducing the light path of starlight. The deployment of multiconjugate adaptive optics on large aperture telescopes world-wide will require the use of three to five sodium laser guide stars in order to achieve uniform correction over the aperture with a high Strehl value. Current estimates place the minimum required laser power at 10 W per laser for a continuous wave source. In addition, the lasers need to be compact, efficient, robust and turnkey.
{"title":"Compact fiber laser approach to generating 589 nm laser guide stars","authors":"D. M. Pennington, R. Beach, J. Dawson, A. Drobshoff, Z. Liao, S. Payne, D. Bonaccini, W. Hackenberg, L. Taylor","doi":"10.1109/CLEOE.2003.1313802","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313802","url":null,"abstract":"We are developing an all-fiber laser system for generating 589 nm light for laser-guided adaptive optics. If only natural stars can be used to measure the turbulence in the Earth's atmosphere, at most a few percent of the sky is accessible to adaptive optics correction. Laser guide stars are therefore crucial to the broad use of adaptive optics, because they facilitate access to a large fraction of possible locations on the sky. In particular, lasers tuned to the 589 nm resonance line of atomic sodium are able to create an artificial beacon at altitudes of 95-105 km, thus coming as close as possible to reproducing the light path of starlight. The deployment of multiconjugate adaptive optics on large aperture telescopes world-wide will require the use of three to five sodium laser guide stars in order to achieve uniform correction over the aperture with a high Strehl value. Current estimates place the minimum required laser power at 10 W per laser for a continuous wave source. In addition, the lasers need to be compact, efficient, robust and turnkey.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"112 1","pages":"730-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72958150","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1313707
T. Kossek, P. Szczepański, R. Paszkiewicz
In this paper, the influence of introducing of passive region (saturable absorber) on threshold circular mode generation was discussed. The theoretical model of threshold operation of the circular grating surface-emitting (CG-SEL) laser taking into account effect of spatial hole burning and reflection from integrated outcoupler was proposed. A semiclassical model based on vector-wave self-consistent nonlinear coupled-mode equations was developed. Analysis of laser characteristics leads us to conclusion that the introduced saturable absorber causes azimutal mode discrimination and also bistable operation.
{"title":"Above threshold analysis of mode discrimination in circular grating surface-emitting lasers with saturable absorber","authors":"T. Kossek, P. Szczepański, R. Paszkiewicz","doi":"10.1109/CLEOE.2003.1313707","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313707","url":null,"abstract":"In this paper, the influence of introducing of passive region (saturable absorber) on threshold circular mode generation was discussed. The theoretical model of threshold operation of the circular grating surface-emitting (CG-SEL) laser taking into account effect of spatial hole burning and reflection from integrated outcoupler was proposed. A semiclassical model based on vector-wave self-consistent nonlinear coupled-mode equations was developed. Analysis of laser characteristics leads us to conclusion that the introduced saturable absorber causes azimutal mode discrimination and also bistable operation.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"20 1","pages":"646-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73038506","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1313505
O. Tcherbakoff, E. Mevel, A. Zayr, J. Plumridge, E. Constant
We observe two photon transitions induced by high order harmonics of a Titanium Sapphire laser with harmonic orders larger than 11 (i. e. h < 73 nm). We generate high order harmonics by focussing an 800 nm, 50 fs pulse into a I cm gas cell (filled with Xe, Kr or Ar) and use this harmonics to observe two XUV photon processes. After spectral filtering of the harmonic beam (by transmission through a thin Aluminium filter that only transmits harmonics with orders higher than 1 I), the XUV beam is focussed onto a second rare gas jet with a 5 cm focal length, platinium coated mirror. This gaz jet is located inside the sensitive zone of a time of flight mass spectrometer that allows us to detect singly and doubly charged ions. When the XUV beam is focussed into the sensitive zone of the spectrometer, one could observe doubly charged ions (we could observe A?, K? and Xe” by using Ar, Kr or Xe). This signal disapears when the XUV beam crosses the sensitive zone without being focussed which shows that the observed processes are intensity dependent. Among the several pathes that could lead to observation of such doubly charged ions, only two photons transitions involving harmonic order larger than 1 I are consistent with our observations. These transitions can be sequential or direct but both can help measuring the XUV pulse duration via autocorrelation like techniques. 0-7803-7734-6/03/$20.0
{"title":"XUV induced non-linear transitions","authors":"O. Tcherbakoff, E. Mevel, A. Zayr, J. Plumridge, E. Constant","doi":"10.1109/CLEOE.2003.1313505","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313505","url":null,"abstract":"We observe two photon transitions induced by high order harmonics of a Titanium Sapphire laser with harmonic orders larger than 11 (i. e. h < 73 nm). We generate high order harmonics by focussing an 800 nm, 50 fs pulse into a I cm gas cell (filled with Xe, Kr or Ar) and use this harmonics to observe two XUV photon processes. After spectral filtering of the harmonic beam (by transmission through a thin Aluminium filter that only transmits harmonics with orders higher than 1 I), the XUV beam is focussed onto a second rare gas jet with a 5 cm focal length, platinium coated mirror. This gaz jet is located inside the sensitive zone of a time of flight mass spectrometer that allows us to detect singly and doubly charged ions. When the XUV beam is focussed into the sensitive zone of the spectrometer, one could observe doubly charged ions (we could observe A?, K? and Xe” by using Ar, Kr or Xe). This signal disapears when the XUV beam crosses the sensitive zone without being focussed which shows that the observed processes are intensity dependent. Among the several pathes that could lead to observation of such doubly charged ions, only two photons transitions involving harmonic order larger than 1 I are consistent with our observations. These transitions can be sequential or direct but both can help measuring the XUV pulse duration via autocorrelation like techniques. 0-7803-7734-6/03/$20.0","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"80 1","pages":"442-442"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74112159","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}
Pub Date : 2003-06-22DOI: 10.1109/CLEOE.2003.1313573
C. Gawith, G. Emmerson, S. Watts, V. Albanis, M. Ibsen, R.B. Williams, P. Smith, S. McMeekin, J. Bonar, R. Laming
We present a single-step technique for defining channel waveguides with internal Bragg gratings in photosensitive germanosilica-on-silicon using two interfering focussed UV beams. Early devices exhibit reflection intensities of 80% with <0.15 nm bandwidth.
{"title":"Single-step definition of channel waveguides with integral Bragg gratings in germanosilica-on-silicon wafers by direct UV writing","authors":"C. Gawith, G. Emmerson, S. Watts, V. Albanis, M. Ibsen, R.B. Williams, P. Smith, S. McMeekin, J. Bonar, R. Laming","doi":"10.1109/CLEOE.2003.1313573","DOIUrl":"https://doi.org/10.1109/CLEOE.2003.1313573","url":null,"abstract":"We present a single-step technique for defining channel waveguides with internal Bragg gratings in photosensitive germanosilica-on-silicon using two interfering focussed UV beams. Early devices exhibit reflection intensities of 80% with <0.15 nm bandwidth.","PeriodicalId":6370,"journal":{"name":"2003 Conference on Lasers and Electro-Optics Europe (CLEO/Europe 2003) (IEEE Cat. No.03TH8666)","volume":"25 4","pages":"511-"},"PeriodicalIF":0.0,"publicationDate":"2003-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72576282","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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