Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942745
C. de Mauro, D. Alfieri, M. Arrigoni, D. Armstrong, F. Pavone
Thanks to the non linearity arising when femtosecond pulses are coupled into Photonic Crystal Fibers (PCFs), continuum spectra can be generated starting from single wavelength lasers. Multiphoton microscopy [1], fluorescence lifetime imaging [2], stimulated emission depletion microscopy [3], and optical coherence tomography [4] have been previously realized using such kind of excitation source, covering most of the state-of-the-art biological imaging techniques. Usually the properties of PCFs in terms of anomalous dispersion and high non linearity are exploited to produce the greater spectral broadening. We choose instead to pump a PCF with a selected dispersion profile in the normal dispersion region. This approach results in effects: reduction of non linearity, flat spectrum at the output and reduced amplitude noise in the different spectral bands generated [5]. We characterize the imaging performances of the system mainly in two ways. First of all by measuring the Point Spread Function (PSF) using sub-resolution fluorescent beads: sub micron radial resolution and micron optical sectioning is achieved in the whole spectrum. Most important, we compared the images obtained with a 30nm wide band selected from the continuum around 780nm with the ones using a single wavelength 785nm source (see Fig.1): Signal to Noise Ratio (SNR) and image quality are comparable, thus demonstrating the validity of our approach. The spectrum at the output of the fiber can then be arbitrarily shaped to select the desired excitation wavelength in the range from 700nm to 1000nm, where the two photon cross sections of the most common fluorophores are peaked.
{"title":"PCF infrared continuum for multiwavelength two photon microscopy","authors":"C. de Mauro, D. Alfieri, M. Arrigoni, D. Armstrong, F. Pavone","doi":"10.1109/CLEOE.2011.5942745","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942745","url":null,"abstract":"Thanks to the non linearity arising when femtosecond pulses are coupled into Photonic Crystal Fibers (PCFs), continuum spectra can be generated starting from single wavelength lasers. Multiphoton microscopy [1], fluorescence lifetime imaging [2], stimulated emission depletion microscopy [3], and optical coherence tomography [4] have been previously realized using such kind of excitation source, covering most of the state-of-the-art biological imaging techniques. Usually the properties of PCFs in terms of anomalous dispersion and high non linearity are exploited to produce the greater spectral broadening. We choose instead to pump a PCF with a selected dispersion profile in the normal dispersion region. This approach results in effects: reduction of non linearity, flat spectrum at the output and reduced amplitude noise in the different spectral bands generated [5]. We characterize the imaging performances of the system mainly in two ways. First of all by measuring the Point Spread Function (PSF) using sub-resolution fluorescent beads: sub micron radial resolution and micron optical sectioning is achieved in the whole spectrum. Most important, we compared the images obtained with a 30nm wide band selected from the continuum around 780nm with the ones using a single wavelength 785nm source (see Fig.1): Signal to Noise Ratio (SNR) and image quality are comparable, thus demonstrating the validity of our approach. The spectrum at the output of the fiber can then be arbitrarily shaped to select the desired excitation wavelength in the range from 700nm to 1000nm, where the two photon cross sections of the most common fluorophores are peaked.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76337980","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5943602
A. Ziaeemehr, R. Poursalehi
We studied the effects of nanofiller size on the refractive index and optical transparency of nanoparticle polymer nanocomposite. The size of nanofillers has been considered from 3 up to 30 nm. In a precise calculation of absorption and scattering of polymer matrix, the modified size dependent refractive index is used. In addition, this quantity obtained with considering size dependent surface effects.
{"title":"Optical properties of silver nanoparticle dispersed in polymer matrix","authors":"A. Ziaeemehr, R. Poursalehi","doi":"10.1109/CLEOE.2011.5943602","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943602","url":null,"abstract":"We studied the effects of nanofiller size on the refractive index and optical transparency of nanoparticle polymer nanocomposite. The size of nanofillers has been considered from 3 up to 30 nm. In a precise calculation of absorption and scattering of polymer matrix, the modified size dependent refractive index is used. In addition, this quantity obtained with considering size dependent surface effects.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76037781","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5943202
M. Likhachev, S. Aleshkina, A. V. Shubin, M. Bubnov, E. Dianov, D. Lipatov, A. Guryanov
Large-mode area (LMA) Yb-doped fibers are routinely used in high-power CW and pulsed fiber lasers and amplifiers. Solubility of Yb3+ ions in pure silica glass is rather small; therefore co-doping with Al2O3 is required to suppress clustering. Single-mode operation in LMA fibers (core diameter ∼ 20 µm) is possible, when the refractive index difference between the core and the cladding (Δn) is about 0.002 or less. Both Al2O3 and Yb2O3 have a relatively high molar refractivity (∼0.0025/mol.% and 0.001/wt.%, respectively), and therefore only a small Al2O3 concentration can be incorporated into a highly Yb-doped LMA fiber. Clustering of Yb3+ ions results in photodarkening (PD) - degradation of the laser properties with time due to a grey loss increase. Utilization of the phosphorosilicate glass matrix allows one to suppress PD almost completely (the grey loss due to PD is 10–100 times smaller in comparison with that in the aluminosilicate fiber) [1], but a typical Δn in such fibers is about 0.005–0.015.
{"title":"Large-mode-area highly Yb-doped photodarkening-free Al2O3-P2O5-SiO2-Based fiber","authors":"M. Likhachev, S. Aleshkina, A. V. Shubin, M. Bubnov, E. Dianov, D. Lipatov, A. Guryanov","doi":"10.1109/CLEOE.2011.5943202","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943202","url":null,"abstract":"Large-mode area (LMA) Yb-doped fibers are routinely used in high-power CW and pulsed fiber lasers and amplifiers. Solubility of Yb<sup>3+</sup> ions in pure silica glass is rather small; therefore co-doping with Al<inf>2</inf>O<inf>3</inf> is required to suppress clustering. Single-mode operation in LMA fibers (core diameter ∼ 20 µm) is possible, when the refractive index difference between the core and the cladding (Δn) is about 0.002 or less. Both Al<inf>2</inf>O<inf>3</inf> and Yb<inf>2</inf>O<inf>3</inf> have a relatively high molar refractivity (∼0.0025/mol.% and 0.001/wt.%, respectively), and therefore only a small Al<inf>2</inf>O<inf>3</inf> concentration can be incorporated into a highly Yb-doped LMA fiber. Clustering of Yb<sup>3+</sup> ions results in photodarkening (PD) - degradation of the laser properties with time due to a grey loss increase. Utilization of the phosphorosilicate glass matrix allows one to suppress PD almost completely (the grey loss due to PD is 10–100 times smaller in comparison with that in the aluminosilicate fiber) [1], but a typical Δn in such fibers is about 0.005–0.015.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76084481","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5943371
Y. Rezus, S. Walt, G. Zumofen, A. Renn, S. Gotzinger, V. Sandoghdar
Any study of the light-matter interaction involves photons and matter particles such as atoms. However, the great majority of such experiments have been performed using large ensembles of matter and light particles. Recent advances in quantum optics and nano-optics have made it possible to detect, examine, and manipulate single atoms, ions, or molecules using laser light. Furthermore, single atoms, ions and molecules have become established as sources of single photons by many groups. Nevertheless, experiments on the interaction of single photons with single atoms have been few and restricted to the strong coupling regime in high-finesse cavities. The fundamental challenge in such experiments is to confine light efficiently enough so that the electric field associated with a single photon can lead to atomic excitation. Our recent theoretical and experimental works have indicated that this should be possible using a tightly-focused laser beam [1, 2]. In this presentation, we report for the first time on the spectroscopy of single molecules using a freely-propagating stream of single photons produced by another single molecule placed at a large distance, as sketched in Figure 1a [3].
{"title":"Spectroscopy of a single molecule using single photons emitted by another molecule","authors":"Y. Rezus, S. Walt, G. Zumofen, A. Renn, S. Gotzinger, V. Sandoghdar","doi":"10.1109/CLEOE.2011.5943371","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943371","url":null,"abstract":"Any study of the light-matter interaction involves photons and matter particles such as atoms. However, the great majority of such experiments have been performed using large ensembles of matter and light particles. Recent advances in quantum optics and nano-optics have made it possible to detect, examine, and manipulate single atoms, ions, or molecules using laser light. Furthermore, single atoms, ions and molecules have become established as sources of single photons by many groups. Nevertheless, experiments on the interaction of single photons with single atoms have been few and restricted to the strong coupling regime in high-finesse cavities. The fundamental challenge in such experiments is to confine light efficiently enough so that the electric field associated with a single photon can lead to atomic excitation. Our recent theoretical and experimental works have indicated that this should be possible using a tightly-focused laser beam [1, 2]. In this presentation, we report for the first time on the spectroscopy of single molecules using a freely-propagating stream of single photons produced by another single molecule placed at a large distance, as sketched in Figure 1a [3].","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86925836","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5942812
L. P. Ramirez, D. Papadopoulos, A. Pellegrina, P. Monot, A. Ricci, A. Jullien, X. Chen, J. Rousseau, R. López-Martens, P. Georges, F. Druon
Cross polarized wave generation (XPW) is a well established technique for contrast enhancement of ultrashort pulses in high energy laser systems [1]. Efficient conversion with XPW only occurs at high intensities. Weaker, unconverted pre and post pulses are thus rejected by the second polarizer, thereby improving the temporal contrast of the pulse. XPW has several drawbacks especially in terms of simultaneously achieving high conversion efficiencies and output energies. Limitations in seeding the nonlinear filter with high energies arise from the upper intensity limit of white light generation while high conversion efficiencies require excellent beam quality.
{"title":"High efficient XPW generation for high contrast high energy ultrashort laser pulses","authors":"L. P. Ramirez, D. Papadopoulos, A. Pellegrina, P. Monot, A. Ricci, A. Jullien, X. Chen, J. Rousseau, R. López-Martens, P. Georges, F. Druon","doi":"10.1109/CLEOE.2011.5942812","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942812","url":null,"abstract":"Cross polarized wave generation (XPW) is a well established technique for contrast enhancement of ultrashort pulses in high energy laser systems [1]. Efficient conversion with XPW only occurs at high intensities. Weaker, unconverted pre and post pulses are thus rejected by the second polarizer, thereby improving the temporal contrast of the pulse. XPW has several drawbacks especially in terms of simultaneously achieving high conversion efficiencies and output energies. Limitations in seeding the nonlinear filter with high energies arise from the upper intensity limit of white light generation while high conversion efficiencies require excellent beam quality.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87598311","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5943561
C. McIntyre, G. Oppo, N. Radwell, Y. Noblet, T. Ackemann, W. Firth, P. Paulau
The last few years have seen rapid progress in the creation of cavity solitons in broad-area semiconductor lasers. Such states represent small coherent microlasers which can be controlled by the operator thus making them interesting for optical information processing [1]. Here we investigate Laser Cavity Solitons (LCS) in a Vertical Cavity Surface Emitting Laser (VCSEL) with Frequency Selective Feedback (FSF). In our cavity soliton laser, the phase is not fixed and each LCS can have a different frequency due to disorder. Each LCS therefore has the freedom to choose its own frequency and phase. As such, it seems an interesting question to ask whether two or more of these self-localized states show frequency and phase locking behavior.
{"title":"Frequency and phase locking in a cavity soliton laser","authors":"C. McIntyre, G. Oppo, N. Radwell, Y. Noblet, T. Ackemann, W. Firth, P. Paulau","doi":"10.1109/CLEOE.2011.5943561","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943561","url":null,"abstract":"The last few years have seen rapid progress in the creation of cavity solitons in broad-area semiconductor lasers. Such states represent small coherent microlasers which can be controlled by the operator thus making them interesting for optical information processing [1]. Here we investigate Laser Cavity Solitons (LCS) in a Vertical Cavity Surface Emitting Laser (VCSEL) with Frequency Selective Feedback (FSF). In our cavity soliton laser, the phase is not fixed and each LCS can have a different frequency due to disorder. Each LCS therefore has the freedom to choose its own frequency and phase. As such, it seems an interesting question to ask whether two or more of these self-localized states show frequency and phase locking behavior.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87731572","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5942894
Vicente Durán, P. Clemente, V. Torres‐Company, E. Tajahuerce, J. Lancis, P. Andrés
Ghost imaging (GI) is a novel technique where the optical information of an object is encoded in the correlation of the intensity fluctuations of a light source. Computational GI (CGI) is a variant of the standard procedure that uses a single bucket detector. Recently, we proposed to use CGI to encrypt and transmit the object information to a remote party [1]. The optical encryption scheme shows compressibility and robustness to eavesdropping attacks. The reconstruction algorithm provides a relative low quality images and requires high acquisitions times. A procedure to overcome such limitations is to combine CGI with compressive sampling (CS), an advanced signal processing theory that exploits the redundancy in the structure of most usual images.
{"title":"Optical encryption with compressive ghost imaging","authors":"Vicente Durán, P. Clemente, V. Torres‐Company, E. Tajahuerce, J. Lancis, P. Andrés","doi":"10.1109/CLEOE.2011.5942894","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942894","url":null,"abstract":"Ghost imaging (GI) is a novel technique where the optical information of an object is encoded in the correlation of the intensity fluctuations of a light source. Computational GI (CGI) is a variant of the standard procedure that uses a single bucket detector. Recently, we proposed to use CGI to encrypt and transmit the object information to a remote party [1]. The optical encryption scheme shows compressibility and robustness to eavesdropping attacks. The reconstruction algorithm provides a relative low quality images and requires high acquisitions times. A procedure to overcome such limitations is to combine CGI with compressive sampling (CS), an advanced signal processing theory that exploits the redundancy in the structure of most usual images.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88311484","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5943145
D. Geskus, S. Aravazhi, S. García-Blanco, M. Pollnau
Nowadays two types of optical amplifiers are widely used: rare-earth (RE) doped fiber amplifiers (RDFAs) and semiconductor optical amplifiers (SOAs). RDFAs are not suitable for micro-scale on-chip integration, partly because their gain per unit length is hampered by the combination of small transition cross-sections in RE ions and the restriction to low doping concentrations. SOAs can deliver high gain over short distances, which makes them suitable for providing on-chip gain on silicon wafers. Despite the extraordinarily high material gain in the nm-sized recombination region of a III–V semiconductor, the usually μm-sized confinement of the signal beam results in a poor overlap factor with the active gain region, reducing accordingly the modal gain to a few hundred dB/cm. On the other hand, the typical gain per unit length reported so far for RE-doped integrated waveguides has hardly exceeded a few dB/cm [1, 2], almost two orders of magnitude less than in SOAs.
{"title":"Giant gain in a rare-earth-ion-doped waveguide","authors":"D. Geskus, S. Aravazhi, S. García-Blanco, M. Pollnau","doi":"10.1109/CLEOE.2011.5943145","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943145","url":null,"abstract":"Nowadays two types of optical amplifiers are widely used: rare-earth (RE) doped fiber amplifiers (RDFAs) and semiconductor optical amplifiers (SOAs). RDFAs are not suitable for micro-scale on-chip integration, partly because their gain per unit length is hampered by the combination of small transition cross-sections in RE ions and the restriction to low doping concentrations. SOAs can deliver high gain over short distances, which makes them suitable for providing on-chip gain on silicon wafers. Despite the extraordinarily high material gain in the nm-sized recombination region of a III–V semiconductor, the usually μm-sized confinement of the signal beam results in a poor overlap factor with the active gain region, reducing accordingly the modal gain to a few hundred dB/cm. On the other hand, the typical gain per unit length reported so far for RE-doped integrated waveguides has hardly exceeded a few dB/cm [1, 2], almost two orders of magnitude less than in SOAs.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86444412","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5942502
C. Baer, C. Saraceno, O. Heckl, M. Golling, T. Sudmeyer, K. Beil, C. Krãnkel, K. Petermann, G. Huber, U. Keller
Recent SESAM modelocked thin disk lasers have achieved average powers > 140 W [1] and pulse energies > 25 µJ [2], which is higher than for any other ultrafast oscillator technology. Many experiments in areas such as high field laser science require pulse durations in the sub-100-fs regime, which has not been demonstrated with thin disk lasers so far. The standard thin-disk material Yb:YAG is limited to pulse durations above 700 fs in efficient high power operation. Using Yb:KYW, 22 W of average power were demonstrated in 240-fs pulses [3]. Recently, sesquioxide materials have attracted great attention as a promising candidate for high-power short pulse generation in the thin-disk geometry [4]. For example with Yb:Lu2O3 pulses as short as 329 fs at 40 W [5] and with Yb:LuScO3 pulse durations of 227 fs at 7.2 W [6] have been achieved from a SESAM modelocked thin-disk laser oscillator.
{"title":"CW and modelocked operation of an Yb:(Sc,Y,Lu)2O3 thin-disk laser","authors":"C. Baer, C. Saraceno, O. Heckl, M. Golling, T. Sudmeyer, K. Beil, C. Krãnkel, K. Petermann, G. Huber, U. Keller","doi":"10.1109/CLEOE.2011.5942502","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942502","url":null,"abstract":"Recent SESAM modelocked thin disk lasers have achieved average powers > 140 W [1] and pulse energies > 25 µJ [2], which is higher than for any other ultrafast oscillator technology. Many experiments in areas such as high field laser science require pulse durations in the sub-100-fs regime, which has not been demonstrated with thin disk lasers so far. The standard thin-disk material Yb:YAG is limited to pulse durations above 700 fs in efficient high power operation. Using Yb:KYW, 22 W of average power were demonstrated in 240-fs pulses [3]. Recently, sesquioxide materials have attracted great attention as a promising candidate for high-power short pulse generation in the thin-disk geometry [4]. For example with Yb:Lu2O3 pulses as short as 329 fs at 40 W [5] and with Yb:LuScO3 pulse durations of 227 fs at 7.2 W [6] have been achieved from a SESAM modelocked thin-disk laser oscillator.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83686134","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 : 2011-05-22DOI: 10.1109/CLEOE.2011.5942978
M. Lenz, G. Onishchukov, B. Schmauss, G. Leuchs
Multi-level modulation formats offer a higher spectral efficiency than on-off keying at the same data rate. Most popular is quadrature phase-shift keying (QPSK). However, it is susceptible to amplitude noise and also to phase noise. Two schemes for QPSK phase regeneration have been previously proposed. The first one [1] is based on phase diversity (PD) and uses two phase-sensitive amplifiers in a Mach-Zehnder configuration. The operation of the second scheme [2] is based on four-wave mixing (FWM) of the signal with its higher-order idler (HOI) and two pumps. We have studied the regeneration ability of the two schemes for QPSK phase regeneration with the emphasis on their sensitivity to amplitude noise in the incoming signal. This can be especially important in high-bit-rate transmission systems with strong high-frequency components of the relative intensity noise due to intra-and inter-channel nonlinear effects.
{"title":"Effect of amplitude noise on multi-level phase regeneration","authors":"M. Lenz, G. Onishchukov, B. Schmauss, G. Leuchs","doi":"10.1109/CLEOE.2011.5942978","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942978","url":null,"abstract":"Multi-level modulation formats offer a higher spectral efficiency than on-off keying at the same data rate. Most popular is quadrature phase-shift keying (QPSK). However, it is susceptible to amplitude noise and also to phase noise. Two schemes for QPSK phase regeneration have been previously proposed. The first one [1] is based on phase diversity (PD) and uses two phase-sensitive amplifiers in a Mach-Zehnder configuration. The operation of the second scheme [2] is based on four-wave mixing (FWM) of the signal with its higher-order idler (HOI) and two pumps. We have studied the regeneration ability of the two schemes for QPSK phase regeneration with the emphasis on their sensitivity to amplitude noise in the incoming signal. This can be especially important in high-bit-rate transmission systems with strong high-frequency components of the relative intensity noise due to intra-and inter-channel nonlinear effects.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82872756","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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