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Pierrot S, Salin F. Amplification and compression of temporally shaped picosecond pulses in Yb-doped rod-type fibers. Opt Express 2013; 21:20484-96. [PMID: 24105592 DOI: 10.1364/oe.21.020484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report on a new technique to produce high power sub-picosecond pulses from a fiber amplifier. We use parabolic pulse shaping of 27 ps transform-limited pulses in order to control nonlinear effects in the fiber amplifier. 63 MW, 780 fs pulses with 25 W average power were obtained, and ways to scale the technique to higher peak powers were identified.
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2
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Terenina E, Babigumira BM, Le Mignon G, Bazovkina D, Rousseau S, Salin F, Bendixen C, Mormede P. Association study of molecular polymorphisms in candidate genes related to stress responses with production and meat quality traits in pigs. Domest Anim Endocrinol 2013; 44:81-97. [PMID: 23063408 DOI: 10.1016/j.domaniend.2012.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/07/2012] [Accepted: 09/12/2012] [Indexed: 10/27/2022]
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis exerts a large range of effects on metabolism, the immune system, inflammatory processes, and brain functions. Together with the sympathetic nervous system, it is also the most important stress-responsive neuroendocrine system. Both systems influence production traits, carcass composition, and meat quality. The HPA axis may be a critical target for genetic selection of more robust animals. Indeed, numerous studies in various species have demonstrated the importance of genetic factors in shaping the individual HPA axis phenotype, and genetic polymorphism can be found at each level of the axis, including hormone production by the adrenal cortices under stimulation by adrenocorticotropic hormone (ACTH), hormone bioavailability, or receptor and postreceptor mechanisms. The aim of the present experiment was to extend these findings to the brain neurochemical systems involved in stress responses. To this end, a number of candidate genes were sequenced for molecular polymorphisms and their association was studied with stress neuroendocrine and production traits in a genetically diverse population consisting of 100 female pigs from an advanced intercross (F10-F12) between 2 highly divergent breeds, Large White (LW) and Meishan (MS). The LW breed has a high production potential for lean meat and a low HPA axis activity, and the MS breed has low growth rate, fat carcasses-but large litters of highly viable piglets-and a high HPA axis activity. Candidate genes were chosen in the catecholaminergic and serotonergic pathways, in the pituitary control of cortisol production, among genes previously demonstrated to be differentially expressed in ACTH-stimulated adrenal glands from LW and MS pigs, and in cortisol receptors. Sixty new polymorphisms were found. The association study with carcass and meat quality traits and with endocrine traits showed a number of significant results, such as monoamine oxidase (MAOA) polymorphisms with growth rate (P = 0.01); lean content and intramuscular fat (P < 0.01), which are the most important traits for carcass value; dopamine receptor D3 (DRD3) with carcass composition (P < 0.05); and vasopressin receptor 1B (AVPR1B) with meat quality traits (P ≤ 0.05). The effect of these polymorphisms on neuroendocrine parameters (eg DRD3 and HPA axis or AVPR1B and catecholamines) indicates information regarding their biological mechanism of action.
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Affiliation(s)
- E Terenina
- INRA, UMR444, Laboratory for Cellular Genetics, Castanet-Tolosan, France
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3
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Berciaud S, Rayne F, Kassab S, Jubert C, Faure-Della Corte M, Salin F, Wodrich H, Lafon ME. Adenovirus infections in Bordeaux University Hospital 2008-2010: clinical and virological features. J Clin Virol 2012; 54:302-7. [PMID: 22608365 DOI: 10.1016/j.jcv.2012.04.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/06/2012] [Accepted: 04/17/2012] [Indexed: 10/28/2022]
Abstract
BACKGROUND Transversal epidemiological data on adenovirus infections in a hospital setting, including both immuno-competent and transplanted patients, are limited and rarely contain the application of molecular virology. OBJECTIVES To describe the clinical characteristics and molecular epidemiology of adenovirus infections in Bordeaux University Hospital from 2008 to 2010 (clinical data, viral load and adenovirus species distribution). STUDY DESIGN Adenovirus DNA quantification (qPCR) and typing (sequencing of hexon and protein VI genes and protein VI polymerase chain reaction (PCR) product analysis) were applied retrospectively to 215 clinical samples from 105 adenovirus-infected patients (2008-2010, Bordeaux University Hospital). Clinical data were recovered and analysed for 73 children and 25 adults. RESULTS Viral loads were measured in stools, upper and lower respiratory fluids, blood, urine and digestive tract biopsies; the highest values were observed in stools and respiratory samples. Stool viral loads were comparable whatever the immune status. Adenovirus was typed in 57 patients: species Human adenovirus (HAdV) C dominated (n=36), followed by B (n=15), F (n=5) and D (n=1). We could demonstrate no association between HAdV species and load or clinical severity (observed in most patients). In the immuno-compromised, in contrast to immuno-competent patients, adenovirus infections presented no seasonal variation. Co-infections were frequent: mostly bacterial in immuno-competent children (33%) and viral in immuno-compromised people (34%). CONCLUSIONS The species HAdV C dominates the local ecology, in both respiratory and digestive tract infections, independently of the patient's immune status. Adenovirus infections, often associated with co-infection of bacterial or viral agents, frequently lead to severe clinical consequences in hospital patients.
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Affiliation(s)
- S Berciaud
- Centre Hospitalier Universitaire de Bordeaux, Pediatrics Department, France
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4
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Guichoux E, Lagache L, Wagner S, Chaumeil P, Léger P, Lepais O, Lepoittevin C, Malausa T, Revardel E, Salin F, Petit RJ. Current trends in microsatellite genotyping. Mol Ecol Resour 2011; 11:591-611. [PMID: 21565126 DOI: 10.1111/j.1755-0998.2011.03014.x] [Citation(s) in RCA: 420] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Microsatellites have been popular molecular markers ever since their advent in the late eighties. Despite growing competition from new genotyping and sequencing techniques, the use of these versatile and cost-effective markers continues to increase, boosted by successive technical advances. First, methods for multiplexing PCR have considerably improved over the last years, thereby decreasing genotyping costs and increasing throughput. Second, next-generation sequencing technologies allow the identification of large numbers of microsatellite loci at reduced cost in non-model species. As a consequence, more stringent selection of loci is possible, thereby further enhancing multiplex quality and efficiency. However, current practices are lagging behind. By surveying recently published population genetic studies relying on simple sequence repeats, we show that more than half of the studies lack appropriate quality controls and do not make use of multiplex PCR. To make the most of the latest technical developments, we outline the need for a well-established strategy including standardized high-throughput bench protocols and specific bioinformatic tools, from primer design to allele calling.
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Affiliation(s)
- E Guichoux
- INRA, UMR 1202 Biodiversity Genes & Communities, F-33610 Cestas, France
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Schmidt O, Rothhardt J, Röser F, Linke S, Schreiber T, Rademaker K, Limpert J, Ermeneux S, Yvernault P, Salin F, Tünnermann A. Millijoule pulse energy Q-switched short-length fiber laser. Opt Lett 2007; 32:1551-3. [PMID: 17546185 DOI: 10.1364/ol.32.001551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We report on a Q-switched short-length fiber laser producing 100 W of average output power at 100 kHz repetition rate and pulse durations as short as 17 ns. Up to 2 mJ of energy and sub-10-ns pulse duration are extracted at lower repetition rates. This performance is obtained by employing a rod-type ytterbium-doped photonic crystal fiber with a 70 microm core as gain medium, allowing for very short pulse durations, high energy storage, and emission of a single-transverse-mode beam.
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Affiliation(s)
- O Schmidt
- Friedrich Schiller University Jena, Institute of Applied Physics, Albert-Einstein-Strasse 15, Jena, Germany.
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Manek-Hönninger I, Boullet J, Cardinal T, Guillen F, Ermeneux S, Podgorski M, Bello Doua R, Salin F. Photodarkening and photobleaching of an ytterbium-doped silica double-clad LMA fiber. Opt Express 2007; 15:1606-1611. [PMID: 19532394 DOI: 10.1364/oe.15.001606] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We studied the temporal evolution of the photodarkening effect in an Yb-doped silica LMA fiber. The absorption spectra exhibit an increase in absorption in the visible and in the near infrared spectral range when the fiber is exposed to pump light around 980 nm. We show the influence of the photodarkening on the cw lasing properties of the fiber, and demonstrate photobleaching of the same fiber by exposure to UV light at 355 nm. The corresponding absorption spectra and lasing performances are shown and are entirely comparable to those of a new fiber.
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Limpert J, Schmidt O, Rothhardt J, Röser F, Schreiber T, Tünnermann A, Ermeneux S, Yvernault P, Salin F. Extended single-mode photonic crystal fiber lasers. Opt Express 2006; 14:2715-2720. [PMID: 19516403 DOI: 10.1364/oe.14.002715] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on an ytterbium-doped photonic crystal fiber with a core diameter of 60 microm and mode-field-area of ~2000 microm(2) of the emitted fundamental mode. Together with the short absorption length of 0.5 m this fiber possesses a record low nonlinearity which makes this fiber predestinated for the amplification of short laser pulses to very high peak powers. In a first continuous-wave experiment a power of 320 W has been extracted corresponding to 550 W per meter. To our knowledge this represents the highest power per unit length ever reported for fiber lasers. Furthermore, the robust single-transverse-mode propagation in a passive 100 microm core fiber with a similar design reveals the potential of extended large-mode-area photonic crystal fibers.
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Limpert J, Aguergaray C, Montant S, Manek-Hönninger I, Petit S, Descamps D, Cormier E, Salin F. Ultra-broad bandwidth parametric amplification at degeneracy. Opt Express 2005; 13:7386-7392. [PMID: 19498762 DOI: 10.1364/opex.13.007386] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification.
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Abstract
Laser in situ keratomileusis (LASIK) complications are mainly attributable to imperfect cutting with the mechanical microkeratome. The femtosecond laser is an important challenger because it can provide extremely precise cutting beginning at any corneal point. We analyze the potential of this new tool from the results reported in the literature. The optomechanical control of the impact position provides freer and more effective intrastromal cutting than the blade. The best cutting matrix is obtained with the postage stamp method. If the plasma quality is not perfectly under control, side effects such as tissue streaks and secondary ultraviolet radiations can be observed. For LASIK surgery, femtolaser cutting can offer greater safety, reproducibility, predictability and flexibility. The risk of incomplete or irregular cutting and the free cap risk are reduced. Striae, epithelial defects and interface deposits should be minimized. A better flap congruence can limit the risk of secondary displacement and epithelial ingrowth. The results of making thinner flaps should be more predictable. Other than the high cost of the procedure, laser cutting has very few disadvantages. In 1999, Intralase Corporation introduced the first femtolaser microkeratome on the American market. Approximately 120,000 intra-LASIK procedures have been carried out with fewer cutting complications than with the mechanic blade.
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Affiliation(s)
- D Touboul
- Service d'ophtamologie du CHU de Bordeaux, Université Bordeaux 2, France.
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Limpert J, Deguil-Robin N, Manek-Hönninger I, Salin F, Schreiber T, Liem A, Röser E, Zellmer H, Tünnermann A, Courjaud A, Hönninger C, Mottay E. High-power picosecond fiber amplifier based on nonlinear spectral compression. Opt Lett 2005; 30:714-716. [PMID: 15832915 DOI: 10.1364/ol.30.000714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We report on the rare-earth-doped fiber-based generation of nearly transform-limited 10-ps pulses based on self-phase-modulation-induced spectral compression. An ytterbium-doped low nonlinearity photonic crystal fiber is used as a gain medium. An average power of as much as 97 W at a repetition rate of 47 MHz, corresponding to a peak power as high as 200 kW, was obtained. Furthermore, efficient second-harmonic generation by application of this high-power laser source is discussed.
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Affiliation(s)
- J Limpert
- Celia-Pala, Université Bordeaux 1, 351 Cours de la Libération, F-33405 Talence, France.
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11
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Touboul D, Salin F, Mortemousque B, Courjaud A, Chabassier P, Mottay E, Léger F, Colin J. Effets tissulaires et mécaniques observés lors de l’expérimentation d’un microkératome laser femtoseconde pour la chirurgie réfractive cornéenne. J Fr Ophtalmol 2005; 28:274-84. [PMID: 15883492 DOI: 10.1016/s0181-5512(05)81054-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE Despite progress in mechanical microkeratomes used in refractive surgery, mechanical complications during cutting of the cornea still occur. Cutting by laser could reduce these complications and to date, the femtosecond laser is the only potential candidate for this purpose. Our study reports preliminary results with a femtosecond microkeratome for cutting porcine corneas ex vivo. METHODS We first examined the fundamental principles of the interaction between the femtosecond laser and the corneal stroma, including the volume of tissue lesions, the laser breakdown threshold of the stroma and the laser ablation selectivity. We then analyzed the quality of cutting corneal flaps with the laser, focusing on collateral tissue effects and the roughness of the interfaces observed both histologically and with scanning electron microscopy. RESULTS The photoablative and photodisruptive effects were very similar with the femtosecond laser. This characteristic is specific to ultrashort impulsion photodisruptor lasers and allows for a very precise surgical procedure. The laser-induced breakdown threshold of porcine corneal stroma was found to be 0.55 J/cm2. Collateral tissue lesions were on the submicrometer level. The roughness of the stromal bed was optimal for postage stamp cutting, providing very many contiguous points of impact which were as spherical as possible. CONCLUSION Corneal photodisruption with a femtosecond laser is reproducible and extremely accurate. The optomechanical parameters involved with this technique require great technological skill and should be placed in experienced hands.
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Affiliation(s)
- D Touboul
- Centre des Lasers Intenses et Applications (CELIA), Université Bordeaux-1, Bordeaux.
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12
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Limpert J, Deguil-Robin N, Manek-Hönninger I, Salin F, Röser F, Liem A, Schreiber T, Nolte S, Zellmer H, Tünnermann A, Broeng J, Petersson A, Jakobsen C. High-power rod-type photonic crystal fiber laser. Opt Express 2005; 13:1055-1058. [PMID: 19494970 DOI: 10.1364/opex.13.001055] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report on a novel ytterbium-doped fiber design that combines the advantages of rod and fiber gain media. The fiber design has outer dimensions of a rod laser, meaning a diameter in the range of a few millimeters and a length of just a few tens of centimeters, and includes two important waveguide structures, one for pump radiation and one for laser radiation. We obtained 120-W output power in single-mode beam quality from a 48-cm-long fiber cane that corresponds to an extracted power of 250 W/m. The fiber has significantly reduced nonlinearity, which therefore allows for scalability in the performance of a high-peak-power fiber laser and amplifier system.
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13
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Hugonnot E, Somekh M, Villate D, Salin F, Freysz E. Optical parametric chirped pulse amplification and spectral shaping of a continuum generated in a photonic band gap fiber. Opt Express 2004; 12:2397-2403. [PMID: 19475076 DOI: 10.1364/opex.12.002397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A chirped pulse, spectrally broadened in a photonic bandgap optical fiber by 120 fs Ti:Sapphire laser pulses, is parametrically amplified in a BBO crystal pumped by a frequency doubled nanosecond Nd:YAG laser pulse. Without changing the frequency of the Ti:Sapphire, a spectral tunability of the amplified pulses is demonstrated. The possibility to achieve broader spectral range amplification is confirmed for a non-collinear pump-signal interaction geometry. For optimal non-collinear interaction geometry, the pulse duration of the original and amplified pulse are similar. Finally, we demonstrate that the combination of two BBO crystals makes it possible to spectrally shape the amplified pulses.
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14
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Olivié G, Villate D, Videau L, Freysz E, Salin F. Temporal characterization of short pulses stretched by fiber Bragg gratings. Opt Lett 2003; 28:1585-1587. [PMID: 12956387 DOI: 10.1364/ol.28.001585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Short femtosecond pulses at 1054 nm are stretched up to 400 ps by long broadband chirped-fiber Bragg gratings. The temporal profile of the reflected pulses is measured with a cross-correlation scheme. The advantage of this technique over the usual spectral measurements is its high sensitivity, since the temporal profile of reflected pulses is revealed to be strongly affected by the presence of defects in the grating. We show that this method is a good test of the quality of fiber Bragg gratings.
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Affiliation(s)
- G Olivié
- Commissariat à l'Energie Atomique, Centre d'Etudes Scientifiques et Techniques d'Aquitaine, B.P. 2, 33114 Le Barp, France.
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15
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Hansen SB, Shlyaptseva AS, Faenov AY, Skobelev IY, Magunov AI, Pikuz TA, Blasco F, Dorchies F, Stenz C, Salin F, Auguste T, Dobosz S, Monot P, D' Oliveira P, Hulin S, Safronova UI, Fournier KB. Hot-electron influence on L-shell spectra of multicharged Kr ions generated in clusters irradiated by femtosecond laser pulses. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 66:046412. [PMID: 12443335 DOI: 10.1103/physreve.66.046412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2002] [Indexed: 05/24/2023]
Abstract
Strong L-shell x-ray emission has been obtained from Kr clusters formed in gas jets and irradiated by 60-500-fs laser pulses. Spectral lines from the F-, Ne- Na-, and Mg-like charge states of Kr have been identified from highly resolved x-ray spectra. Spectral line intensities are used in conjunction with a detailed time-dependent collisional-radiative model to diagnose the electron distribution functions of plasmas formed in various gas jet nozzles with various laser pulse durations. It is shown that L-shell spectra formed by relatively long nanosecond-laser pulses can be well described by a steady-state model without hot electrons when opacity effects are included. In contrast, adequate modeling of L-shell spectra from highly transient and inhomogeneous femtosecond-laser plasmas requires including the influence of hot electrons. It is shown that femtosecond-laser interaction with gas jets from conical nozzles produces plasmas with higher ionization balances than plasmas formed by gas jets from Laval nozzles, in agreement with previous work for femtosecond laser interaction with Ar clusters.
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Affiliation(s)
- S B Hansen
- Physics Department/220, University of Nevada, Reno 89557, USA
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Constant E, Mével E, Zaïr A, Bagnoud V, Salin F. Toward sub-femtosecond pump-probe experiments : A dispersionless autocorrelator with attosecond resolution. ACTA ACUST UNITED AC 2001. [DOI: 10.1051/jp4:20012105] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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18
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Druon F, Balembois F, Georges P, Brun A, Courjaud A, Hönninger C, Salin F, Aron A, Mougel F, Aka G, Vivien D. Generation of 90-fs pulses from a mode-locked diode-pumped Yb(3+):Ca(4)GdO(BO(3))(3) laser. Opt Lett 2000; 25:423-425. [PMID: 18059900 DOI: 10.1364/ol.25.000423] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
A diode-pumped Yb>(3+):Ca(4)GdO(BO>(3))(3) (Yb:GdCOB) laser generating 90-fs pulses at a center wavelength of 1045 nm is demonstrated. This is, to our knowledge, the shortest pulse duration obtained from an ytterbium laser with a crystalline host. This laser is mode locked with a high-finesse semiconductor saturable-absorber mirror and emits 40 mW of average power at a repetition rate of 100 MHz.
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Dorrer C, de Beauvoir B, Le Blanc C, Ranc S, Rousseau JP, Rousseau P, Chambaret JP, Salin F. Single-shot real-time characterization of chirped-pulse amplification systems by spectral phase interferometry for direct electric-field reconstruction. Opt Lett 1999; 24:1644-1646. [PMID: 18079891 DOI: 10.1364/ol.24.001644] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We characterize chirped-pulse amplification systems by using spectral phase interferometry for direct electric-field reconstruction. For the first time to the authors' knowledge, single-shot real-time operation has been obtained for this technique, leading to a fast and accurate optimization of these systems.
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Affiliation(s)
- C Dorrer
- Laboratoire d'Optique Appliquée, Batterie de l'Yvette, 91761 Palaiseau Cedex, France
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20
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Fournier S, López-Martens R, Le Blanc C, Baubeau E, Salin F. Solitonlike pulse shortening in a femtosecond parametric amplifier. Opt Lett 1998; 23:627-629. [PMID: 18084598 DOI: 10.1364/ol.23.000627] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We demonstrate numerically that simultaneous second-harmonic generation and moderate group-velocity mismatch can lead to spontaneous nonlinear shortening during parametric amplification. As an experimental proof we present the results of twofold self-compression of signal pulses in a beta-barium borate parametric amplifier pumped by either 40- or 80-fs pulses from a Ti:sapphire laser.
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Salin F, Blanc CL, Squier J, Barty C. Thermal eigenmode amplifiers for diffraction-limited amplification of ultrashort pulses. Opt Lett 1998; 23:718-720. [PMID: 18087320 DOI: 10.1364/ol.23.000718] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The design of high-repetition, high-average power, multipass amplifiers in which the pump power induced thermal lensing within the amplifier is used to create an equivalent lens waveguide for the production of diffraction-limited beams is analyzed.
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Dorrer C, Salin F, Verluise F, Huignard JP. Programmable phase control of femtosecond pulses by use of a nonpixelated spatial light modulator. Opt Lett 1998; 23:709-711. [PMID: 18087317 DOI: 10.1364/ol.23.000709] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Programmable spectral phase modulation of femtosecond pulses by use of a nonpixelated spatial light modulator is reported. This light valve, based on the optical addressing of a continuous layer of liquid crystal, allows the operation of spectral phase modulation when optical frequency components are spatially dispersed within a grating-and-lenses pulse-shaping apparatus. Characterization and feedback control of this device were determined by use of spectral interferometry. Demonstrations of the capabilities of this device are given in the spectral and the temporal domains, and recompression of chirped pulses was performed.
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23
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Chambaret JP, Le Blanc C, Chériaux G, Curley P, Darpentigny G, Rousseau P, Hamoniaux G, Antonetti A, Salin F. Generation of 25-TW, 32-fs pulses at 10 Hz. Opt Lett 1996; 21:1921-1923. [PMID: 19881846 DOI: 10.1364/ol.21.001921] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have developed a femtosecond laser chain that generates 25-TW pulses of less than 35 fs at 10 Hz with focused intensities higher than 5 x 10(19) W/cm(2) and an average power of 8 W. This system is optimized for a broad transmission bandwidth and includes an aberration-free stretcher compressor.
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Loiseaux B, Delboulbé A, Huignard JP, Tournois P, Cheriaux G, Salin F. Characterization of perpendicular chirped phase volume grating pairs for laser pulse stretching. Opt Lett 1996; 21:806-808. [PMID: 19876165 DOI: 10.1364/ol.21.000806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the characterization of a new pulse stretcher that provides a linear and positive variation of the group delay as a function of the optical frequency. It consists of a perpendicular chirped-grating pair introduced by Tournois [Opt. Commun. 106, 253 (1994)] that allows 20-fs pulses to be stretched to 100 ps. The system is tested by short-pulse spectral interferometry. We designed and realized the chirped gratings by phase volume holographic recording in a highly efficient photopolymer.
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Cheriaux G, Rousseau P, Salin F, Chambaret JP, Walker B, Dimauro LF. Aberration-free stretcher design for ultrashort-pulse amplification. Opt Lett 1996; 21:414-416. [PMID: 19865423 DOI: 10.1364/ol.21.000414] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel aberration-free pulse stretcher design is presented. This system permits the stretching of a 30-fs pulse to 300 ps and recompression to a duration of 33 fs, limited by the spectral clipping.
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Nibbering ET, Curley PF, Grillon G, Prade BS, Franco MA, Salin F, Mysyrowicz A. Conical emission from self-guided femtosecond pulses in air. Opt Lett 1996; 21:62-65. [PMID: 19865305 DOI: 10.1364/ol.21.000062] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Conical emission in the forward direction is observed from intense femtosecond light pulses propagating through air over long distances. The conical emission is attributed to Cerenkov radiation from a dynamic self-guiding structure consisting of a weakly ionized core surrounded by Kerr cladding.
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Socaciu C, Faye M, Salin F, Pauly G, Gleizes M. In vitro yeast (Saccharomyces cerevisiae) presqualene and squalene synthesis related to substrate and cofactor availability. C R Acad Sci III 1995; 318:919-26. [PMID: 8521075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Squalene synthase catalyses the synthesis of squalene from trans-farnesyl diphosphate in 2 separate steps requiring NAD(P)H. The kinetics of this enzyme in different fractions extracted from a wild-type Saccharomyces cerevisiae were studied. Although this protein is known to be a membrane-bound enzyme, we have found a cytosolic squalene synthase activity besides the microsomal enzyme. A spectrophotometric enzyme assay, not involving isotopic labelling, was established. The relative synthesis of presqualene and squalene was evaluated by using different substrate and cofactor concentrations during the incubation. The involvement of a single catalytic site promoting the 2 reactions of squalene synthesis is suggested.
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Affiliation(s)
- C Socaciu
- Department Biochimie vegetale, Universitatea de Stiinte Agricole, Cluj-Napoca, Romania
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Abstract
We show that thermal aberration in optically pumped solid-state lasers can lead to the breakup of the beam profile. Kerr lensing present in the self-mode-locked regime tends to reduce the beam size in the laser material; such a beam is less sensitive to the thermal aberration, and its shape becomes free of secondary lobes. The thermal aberration has also the effect of moving the optimal operation point for self-mode locking. Experimental results obtained with a Ti:sapphire laser support our theoretical results.
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Balembois F, Georges P, Salin F, Brun A. High-repetition-rate cw-pumped Cr(3+):LiSrAlF(6) femtosecond regenerative amplifier. Opt Lett 1993; 18:1250-1252. [PMID: 19823348 DOI: 10.1364/ol.18.001250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have developed a cw krypton-ion-laser-pumped Cr(3+):LiSrAlF(6) regenerative amplifier for femtosecond pulses operating at a 5-kHz repetition rate. After recompression, we obtained 3.6-microJ, 170-fs pulses at 825 nm. By focusing these pulses in a cell of water, we generated a white-light continuum.
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Abstract
We report the use of gain guiding in a Ti:Al(2)O(3) rod to produce 150-mJ tunable pulses from a flat-flat resonator with an excellent efficiency. The output beam is Gaussian and 1.3 times diffraction limited.
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Abstract
We demonstrate the stretching of 100- fs pulses by a factor of 12,000, using standard-size optical elements. These stretched pulses are then amplified and recompressed to their initial duration.
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Salin F, Squier J, Mourou G, Vaillancourt G. Multikilohertz Ti:A1(2)O(3) amplifier for high-power femtosecond pulses. Opt Lett 1991; 16:1964-1966. [PMID: 19784196 DOI: 10.1364/ol.16.001964] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We amplified femtosecond pulses at repetition rates of as much as 7.2 kHz in a Ti:Al(2)O(3) regenerative amplifier pumped by a frequency-doubled Q-switched Nd:YLF laser. Energies of as much as 1 mJ at 1 kHz and 85 microJ at 7.2 kHz in a 150-fs pulse have been obtained. This source was used to produce 1 W of femtosecond white light through spectral continuum generation.
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Salin F, Squier J, Piché M. Mode locking of Ti:AI(2)O(3) lasers and self-focusing: a Gaussian approximation. Opt Lett 1991; 16:1674-1676. [PMID: 19784105 DOI: 10.1364/ol.16.001674] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present an ABCD matrix model showing that self-focusing in the laser rod leads to modifications of the Gaussian beam parameters in cw-pumped Ti:Al(2)O(3) lasers. Stabilization of self-mode-locking should result from these beam perturbations. Experimental measurements of beam modifications supporting this model are presented. The role of gain guiding is studied, and the limitations of the model are discussed.
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Abstract
We have constructed a self-mode-locked Ti:Al(2)O(3) laser that produces 100-fs pulses at 750 nm. These pulses are then amplified in a Ti:Al(2)O(3) regenerative amplifier to the millijoule energy level. 105-fs, 10-GW pulses have been produced.
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Affiliation(s)
- J Squier
- Ultrafast Science Laboratory, University of Michigan, 2200 Bonisteel, Room 1006, Ann Arbor, Michigan 48109-2099, USA
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Georges P, Estable F, Salin F, Poizat JP, Grangier P, Brun A. High-efficiency multipass Ti:sapphire amplifiers for a continuous-wave single-mode laser. Opt Lett 1991; 16:144-146. [PMID: 19773863 DOI: 10.1364/ol.16.000144] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present the amplification of a continuous-wave single-mode ring dye laser in Ti:sapphire. A peak gain of 2 x 10(6) has been obtained in a passive multipass amplifier, which yielded 20-nsec pulses of 0.7-mJ energy at 780 nm. We discuss the advantages of this passive multipass amplifier in comparison with a regenerative amplifier that we have also developed. By second-harmonic generation we obtained high-peak-power UV pulses from the amplified single-mode laser.
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Squier J, Salin F, Coe S, Bado P, Mourou G. Characteristics of an actively mode-locked 2-psec Ti:sapphire laser operating in the 1-microm wavelength regime. Opt Lett 1991; 16:85-87. [PMID: 19773845 DOI: 10.1364/ol.16.000085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We examine the performance of an actively mode-locked Ti:sapphire laser operating in the 1-microm wavelength regime. Pulse durations of 1.7 psec are produced with an average output power of 400 mW. With the use of external dispersion compensation this pulse width has been further reduced to 850 fsec.
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Salin F, Grangier P, Georges P, Brun A. Pulse propagation near zero group-velocity dispersion in a femtosecond dye laser. Opt Lett 1990; 15:1374-1376. [PMID: 19771095 DOI: 10.1364/ol.15.001374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The propagation of femtosecond pulses in a colliding-pulse mode-locked dye laser near zero group-velocity dispersion is studied. The pulse spectrum is shown to exhibit a double-peak structure. This structure and its dependence on the intracavity dispersion can be explained by nonlinear pulse propagation near zero dispersion. A value for the third-order dispersion of the laser cavity is deduced and is found to be predominant for pulses shorter than 50 fsec.
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Abstract
Beating is observed when the two output beams from a colliding-pulse mode-locked laser are recombined outside the cavity. This beating is attributed to nonlinear dephasing in the saturable absorber. An explanation in terms of the soliton period variation is given. The experimental results show good agreement with the predictions of the nonlinear Schrödinger equation.
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Georges P, Salin F, Saux GL, Roger G, Brun A. Femtosecond pulses at 800 nm by passive mode locking of Rhodamine 700. Opt Lett 1990; 15:446-448. [PMID: 19767971 DOI: 10.1364/ol.15.000446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the passive mode locking of a Rhodamine 700 dye laser in the near infrared. Using a short cavity in order to avoid multiple pulses and by adjusting the intracavity dispersion, we have produced 50-fsec pulses at 800 nm with HITCI as the saturable absorber.
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Affiliation(s)
- P Georges
- Institut d'Optique Théorique et Appliquee, Université Paris-Sud, Centre National de Recherche Scientifique, U.A. 14, B.P. 147, 91403 Orsay Cédex, France
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Georges P, Salin F, Brun A. Generation of 36-fsec pulses near 775 nm from a colliding-pulse passively mode-locked dye laser. Opt Lett 1989; 14:940-942. [PMID: 19753018 DOI: 10.1364/ol.14.000940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report the passive mode locking of a cw Rhodamine 700 dye laser using the saturable absorber DDI. Pulses as short as 36 fsec near 775 nm have been produced in a colliding-pulse mode-locked dye laser with adjustable intracavity group-velocity dispersion.
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Salin F, Saux GL, Georges P, Brun A, Bagnall C, Zarzycki J. Efficient tunable solid-state laser near 630 nm using sulforhodamine 640-doped silica gel. Opt Lett 1989; 14:785-787. [PMID: 19752967 DOI: 10.1364/ol.14.000785] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Lasing is observed near 630 nm in a sulforhodamine 640-doped silica gel pumped by frequency-doubled radiation from a Q-switched Nd:YAG laser. A conversion efficiency of 20% is obtained. The laser wavelength is tunable over 40 nm.
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Reynaud F, Salin F, Barthelemy A. Measurement of phase shifts introduced by nonlinear optical phenomena on subpicosecond pulses. Opt Lett 1989; 14:275-277. [PMID: 19749893 DOI: 10.1364/ol.14.000275] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A new method for the coherent characterization of subpicosecond optical pulses after propagation through a nonlinear medium (i.e., with frequency broadening) is described. The phase shift on a single pulse introduced by the nonlinearity can be measured with a high dynamic range. We report as one application of this technique a measurement of the self-phase modulation incurred by an 800-fsec pulse after the pulse propagates along a dispersive single-mode optical fiber.
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Saux GL, Salin F, Georges P, Roger G, Brun A. Measurement of the nonlinear index n(2) of BSO crystals. Appl Opt 1988; 27:2812-2813. [PMID: 20531841 DOI: 10.1364/ao.27.002812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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Abstract
We present a method allowing measurement of the kinetics of the optical Kcrr effect in transparent media using a single femtosecond pulse. This method is based on a spectrotemporal transformation. We describe the experimental results obtained for ultrafast and noninstantaneous responses.
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Salin F, Grangier P, Roger G, Brun A. Experimental observation of nonsymmetrical N=2 solitons in a femtosecond laser. Phys Rev Lett 1988; 60:569-572. [PMID: 10038586 DOI: 10.1103/physrevlett.60.569] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Abstract
We demonstrate the possibility of a 52-fs pulse single-shot measurement by using the spatial analysis of the second harmonic beam produced in an optical autocorrelator. We show that this method gives means of optimizing low repetition rate femtosecond amplifiers.
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Salin F, Grangier P, Roger G, Brun A. Observation of high-order solitons directly produced by a femtosecond ring laser. Phys Rev Lett 1986; 56:1132-1135. [PMID: 10032578 DOI: 10.1103/physrevlett.56.1132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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